A week after his fifth birthday, Izuku has his last sleepover.
Kacchan has slept over before, and the Bakugou household was once a second home to Izuku. Mum has plenty of photos of them as toddlers, curled around each other, sharing a blanket.
Mum doesn’t know that Kacchan has changed since his quirk manifested. She doesn’t know about riverside Saturdays, when the neighbourhood boys push him into the mud over and over again, laughing as Kacchan holds him down. She doesn’t know that Izuku is intimately familiar with the feel Kacchan’s quirk detonating against his skin. She doesn’t know that lately Izuku feels sick after spending time with him, a weight in his stomach that was never there before.
But Izuku doesn’t have the words to explain that. He doesn’t think he would, even if he could. Kacchan is the best friend he’ll ever have, and Izuku will always love him, no matter how angry Kacchan gets.
When Mitsuki and Inko arrange for them to have another sleepover, Izuku goes quiet and doesn’t bounce off the walls with excitement. Inko, too busy checking the fridge for groceries, phone balanced in the crook of her neck, doesn’t notice.
Kacchan is quiet too. Even when they’re in Izuku’s room with the door closed behind them, out of the adults’ view, Kacchan is strangely silent.
“Kacchan.” Izuku whispers, even though the door is closed and the TV in the living room is cranked up loud. “Kacchan, are you awake?”
Kacchan groans. “Yeah, I’m awake.”
“Are you alright?”
“Don’t ask me that, Deku.”
Izuku shimmies out of bed and onto the floor. He curls up on the edge of Kacchan’s futon, stares at his scrunched up face, and waits.
“Do you know what fusions are?” Kacchan asks.
Izuku lights up. “Yeah! It’s when two heroes fuse into one really strong hero to take down villains. The Water-Horse heroes are my favourite.”
“Mum said everyone can fuse, not just heroes. Even us. We’re old enough to do it.”
Izuku blinks. Fusion has always been something reserved for heroes. He knows everyone does it, has seen cartoon characters on TV fuse, but he’s fixated on heroes. Everything else is background noise.
“Do—do you want to?” Izuku asks. “Kacchan, do you want to fuse?”
“Like I’d need you to get any stronger,” Kacchan growls, turning away.
Izuku tucks his face in his knees. He knows he doesn’t have much to offer—his quirk hasn’t manifested yet, and he’s shorter and slower than the other boys, and Kacchan is already so amazing, but …
But he means something to Kacchan. Or he used to. He used to be a member of the Bakugou Katsuki Hero Agency, used to be able to sprawl on the other side of Kacchan’s futon and know he belonged there, instead of having to curl up like he is now, taking up as little space as possible and hoping Kacchan forgets to be mad.
“Yeah,” Kacchan says abruptly, almost like a challenge. “Fine. Let’s fuse.”
Izuku bounces onto his elbows. “Really?”
“I already said fine, didn’t I?”
They sit there, staring at each other for a long moment. And then Izuku says, “Is it working?”
“No, it’s not working!”
“I’ve never done this before.”
Izuku tries to think back to the fusions he’s seen on TV. The Water Horse heroes were married and they had fused so many times before that they could do it on command. But he remembers seeing people on TV fuse for the first time. It’s always special.
Fusion doesn’t just happen. Everyone involved has to agree to it, and get real close, and maybe hold hands. Izuku fuzzily remembers lots of spins and turns and twists, too.
“I think we have to dance,” Izuku says. “That’s how you fuse.”
Kacchan screws up his nose, but reluctantly nods. “Yeah. I think I remember that too.”
They get up and hold hands. Kacchan’s palms are sweaty and too warm. It reminds Izuku of when they were younger, Kacchan clasping his hand tightly as they raced through the woods in search of beetles to capture or villains to defeat. He misses those days.
They clumsily begin moving in circles around his bedroom. Kacchan pulls him closer, leading them, and it reminds Izuku of all the days they spent together, playing and running and clambering over each other.
In that moment, it feels like everything is okay again.
Izuku feels an angry buzzing in his stomach, like he’s eaten a hive of bees. It spreads up his ribs and shoulders and over his ears until his entire body feels loose, disconnected and yet impossibly tethered at the same time.
And then he becomes—more.
He’s still a he. He’s a person with four stubby arms and blotchy freckles. When he looks in the mirror he sees a head full of blond curls and two-toned eyes, one red and one green.
Cain squeezes all four hands into fists. The top two are sweaty and warm, but the bottom hands are dry. He tries using his quirk. Small explosions pop in his top palms.
Something roils inside him at the sight. Katsuki’s fury that he can only partially use his quirk—does that mean his other half is quirkless?—mixes with Deku’s instinctual fear.
Cain can feel how much Katsuki loathes Izuku, a strange kind of hatred echoing up from the deepest part of him. In this form, it feels like self-hatred, and it comes from all directions. With anger and fear choking him, it’s hard to tell where the disgust begins and ends.
Cain hates. He hates himself. He hates the two people who made him. He hates the pops of sounds still detonating in his palm, he hates his stupid light-coloured hair and blotchy skin and the way he feels like throwing up, shivery and weak and with two mashed-together cores, even though people always say fusion is supposed to be something beautiful.
They’re torn apart violently. Izuku curls on carpet, panting roughly. Kacchan is on his futon. He’s crying.
Izuku staggers upright. He stumbles over to Kacchan and holds out his hand. “Are you okay, Kacchan?”
Kacchan stares at the offered hand for a long second. And then he gets up on his own and shoves Izuku. He slams into the bookshelf, All Might figurines raining down around him.
“I don’t need you or your help!”
Mum runs in to see what caused all that noise. Kacchan’s shouting crescendos into screams, and Izuku is sobbing so hard he thinks he’s going to throw up, and then Inko is on the phone, and Mitsuki is bustling into the apartment and grabbing Kacchan tightly around the forearm.
Izuku doesn’t understand. Everything was fine. They were dancing and fizzing like they were full of bubbles. And then, suddenly, everything was all broken.
Kacchan hated being fused together. Izuku had felt his hatred and disgust as if it was his own.
He was quirkless and weak and made Kacchan scream and thrash so hard that Mitsuki had to be called. Fusion was supposed to be beautiful. But Izuku ruined it.
Mum holds him in her lap, rocking him gently. Izuku doesn’t stop crying, even when she carries him into the living room and puts on a recording of the All Might documentary that aired last month.
“You could fuse with me, baby,” she says into his hair. “Most people’s fusions are with their parents when they’re young.”
Izuku shakes his head, beyond words.
“Fusion is supposed to be beautiful, Izuku,“ she says. "You’ll make more friends, and fuse with them, and feel how much they love you. I promise.”
Izuku thinks about the wave of hatred-disgust-fear that rose up when Kacchan realised the extent of their fusion, and buries his wet face in his mum’s shoulder.
He doesn’t want to fuse with anyone ever again.
All Might never fuses with other heroes.
He’s the only pro that doesn’t. Even Endeavour, infamous for his lack of cooperation, keeps several sidekicks on his roster just because their quirks match well with his.
Years ago, when All Might was young and white-eyed, the world’s favourite rookie hero, he would fuse with David Shield. Their fusion was something else: both smart and strong, eternally smiling and more competent than half the hero industry put together.
But those days are behind them. Now, All Might doesn’t fuse with anyone. Not even Sir Nighteye.
They say it’s because All Might is strong enough on his own. The Symbol of Peace doesn’t need to fuse to save the day.
Izuku—who hasn’t fused with anyone since that last terrible sleepover, who watches from a distance as his classmates fuse and unfuse on the playground, chest aching—keeps this fact close to his heart. All Might doesn’t need to fuse. Izuku doesn’t, either.
Kacchan also doesn’t fuse with anyone. Their classmates crowd around his desk, begging to fuse with him, if only to get a taste of Kacchan’s power. He always sneers at them. He’s going to be the Number One Hero, he says. And just like All Might, he’s going to do it alone. Fusions are an excuse for weaker heroes who can’t cut it on their own.
Sometimes, Kacchan catches Izuku’s eye across the classroom. In that microsecond before Kacchan pulls on a glare, Izuku swears he can see something open and searching in his gaze.
He wonders if Kacchan remembers being Cain. He wonders if he misses it.
It was painful. It was terrifying. Izuku hadn’t realised it was possible to feel that bad about himself until he had become a fusion.
But it’s easy to miss something that hurts, if the alternative is this constant lonely nothingness.
Looking at All Might’s malnourished body, the knotted scar engulfing his torso, Izuku realises that this must be the reason All Might doesn’t fuse.
All Might isn’t just a symbol, an idea; he’s a human shield between the villainous underbelly and the rest of Japan. He doesn’t fuse because he has secrets to keep hidden. Because he doesn’t want anyone else to stand up on that pedestal with him, taking blows so that no one else has to.
Looking at this skinny man crouched over his knees, coughing up blood, Izuku realises that All Might’s secret isn’t that he’s weak, even if he struggles to maintain his muscle mass after a few hours; it’s that he’s stronger than Izuku could have ever imagined.
It hurts to know that so much pain is hidden beneath All Might’s smile. Izuku’s decade of isolation is nothing compared to the lifetime All Might has spent on his own.
Izuku is going to accept this power and become strong enough that All Might and the rest of Japan can finally rest, safe and protected in the shadow of his smile.
The sun is cresting the horizon, and the shore is clean of rubbish, and Izuku feels more alive than he has ever felt in his life.
He spots All Might running towards him and almost trips down the garbage pile in his haste to get to him. He sprints across the beach, kicking up sand and crying, salt-sweet tears getting in his mouth.
“All Might,” he calls, even though they’re in public and he knows better to risk drawing attention. “All Might! I did it.”
“Young Izuku,” All Might shouts back, smiling a smile that looks so different to his battle-ready grins, reaching out for Izuku—
His insides fizz. Izuku feels buoyant and filled to bursting with brilliant warmth. He doesn’t think to slow down, even as All Might grows closer. They crash into each other in a blaze of light.
Martys blinks. Looks down at two pairs of hands, tanned and roped with muscle, covered in star-shaped freckles. Realises that Izuku and Toshinori fused.
“Holy shit,” Martys says. Relief brings tears to his eyes and joy almost sends him to his knees.
It has been years since Izuku or Toshinori fused with anyone. They had both thought fusion was something for everyone else. They hadn’t realised how truly isolated they had been until they had met each other and now, standing as Martys, their souls intertwined, he feels ...
Martys laughs, belly-deep and choked with tears, and jumps into the air. He sails high above the beach. Wind whips through his hair, stings his eyes, makes him laugh again, drunk on adrenaline. The city spreads out beneath him, the ocean a flat sheen of blue at his back.
He lands effortlessly. The jump had been all muscle-memory, One for All blazing easily through his body.
Maybe this is how Toshinori can teach Izuku how to wield One for All. As Martys, Izuku will have access to Toshinori’s memories. As Martys, he’ll already know how to use One for All.
Martys’s shoulders hunch and he starts mumbling about what else this fusion could do. A buzz starts in his chest and spreads outward, and then Izuku and All Might are wrenched apart, landing with a thump on the sand.
They stare at each other, dazed and still thrumming with adrenaline, and then they start laughing and lunge across the sand. All Might’s hug is so fierce it lifts Izuku clear off the ground.
They fused. They fused. And it felt like love and joy and strength.
Maybe, Izuku thinks, face smashed into All Might’s shoulder, his stomach still fizzing, maybe fusing isn’t so bad.
After that first accidental collision on the beach, All Might and Izuku keep fusing. As Martys, Izuku can experience first-hand how One for All should feel.
The knowledge fades quickly when he becomes a single entity again. It’s not the most efficient way to train, but neither of them suggest they stop.
When they fuse, Izuku can feel a sudden rush of affection, trust, and safety from All Might. He can feel how grateful he is to have someone else there, another mind to fuse with, all their love and secrets wrapping together.
They don’t talk about it when they unfuse. He’s written essay-length meta posts on hero forums about All Might’s relationship (or lack thereof) with fusion, but he never writes about Martys.
The world has claimed enough of All Might. Their time together is for Izuku. For Toshinori. For the years they’ve both spent alone.
Izuku would never betray that trust.
UA feels like it belongs to another world. The gleaming campus, the staff made up of celebrities, the way All Might smiles at him over the top of his classmates’ heads, secret and nervous and knowing—it’s like something out of a dream.
And, most shockingly, his classmates are so unbelievably kind.
They smile at Izuku and chat with him easily—excitedly, even—and it makes him taste something sharp and sweet on his tongue.
He meets Uraraka and Iida from the Entrance Exam. He’s introduced to Kirishima, who smiles with a mouthful of teeth, so happy Izuku can’t help but feel warm when he looks at him. He sits between classmates at lunch and walks with them to the train station, and when he gets home, his mother takes one look at his beaming smile and breaks down crying.
He misses the first fusions in Class 1-A. After his fight with Kacchan, he spends the rest of the afternoon in Recovery Girl’s office. But the next morning when he arrives to class, everyone is talking about it. Kirishima and Sero, Ashido and Aoyama, Jirou and Kaminari—three new fusions in one class.
In Hero Training that afternoon, he’s paired with Uraraka again. She half-tackles him when their names are called. They’re up again Tsuyu and Hagakure. A dangerous match-up, considering how versatile their quirks are.
Before the exercise begins, Hagakure and Tsuyu twirl around each other in a delicate dance. Tsuyu picks Hagakure up around the waist and lifts her into the air and then, with a blaze of light, they become Chameleon.
Chameleon has pale green skin, shimmering faintly in the sun. Her dark hair is pulled up into twin buns and secured with pink ribbon, and she has horizontal pupils like a frog. She waves at them before blinking out of existence.
“Ah,” Uraraka says. “Shit.”
Izuku squints at the skyscraper looming above them, a dozen plans forming in the back of his mind. Because of the height of the building, Uraraka’s quirk will be useful, but Chameleon can climb and turn invisible. His quirk won’t be much help. After all, he can’t hit what he can’t see, and One for All is too overpowered; he could kill Chameleon with a stray blast.
“Deku,” Uraraka says, sounding almost shy. “Why don’t we fuse too?”
Izuku’s brain stutters to a halt. He blinks at her. “What?”
“We don’t have to if you’re not comfortable fusing! But I just thought—well, we’d have a better chance against them as a fusion, right? But that’s only if you want to. We’ve only known each other for a few days—”
Uraraka is turning red. If we fused, Izuku thinks distantly, we would have the deepest blush in the world.
“You want to fuse with me?” Izuku asks in a small voice.
Uraraka looks at Izuku, really studies him, before reaching out and taking his hand. “Yeah, Deku. I do.”
Aizawa’s voice comes over the intercom: “One minute before the exercise begins.”
Izuku takes a deep, steadying breath. Makes up his mind. “Okay. Okay, let’s fuse.”
Uraraka holds her hands out. Izuku stares at them.
“Deku?” she prompts. “Do you have a different fusing style? We can try something else, if you’d like.”
“N-No, that’s not it! It’s just … I haven’t … I’ve never done this before …” He rubs the back of his head, feeling too-hot and too-small, useless under Uraraka’s gaze. It was always so easy with All Might. The first time they’d fused, it had been an accident, and every time after that had been instinctual, like their quirks were calling out to each other, synching their souls like two halves slotting together.
He’d danced with Kacchan, all those years ago. But he doesn’t want to think about that.
“Oh!” Uraraka smiles gently. “That’s okay. Put your hands in mine. I’ll lead.”
Izuku places his hands atop her’s. She sways them from side-to-side, giggling to herself, and Izuku can’t help but laugh too.
She steps to the right and he follows. They skip in wide circles, hands still intertwined. Slow, at first, then getting faster and faster until they’re spinning tightly around each other, caught in each other’s orbit, and Izuku’s whole mouth is fizzing.
Fusing with Uraraka doesn’t burn, like it did when he fused with Kacchan. It doesn’t feel like a burst of adrenaline, like it had with All Might. It’s light and giddy, a bubbling sensation deep in his soul, and Izuku is swept away with the realisation that they’re friends. Proper friends. He doesn’t know he’s ever had one of those before.
When he opens his eyes again, he’s not a he. He’s a them. And in that moment, they feel as if they could do anything. Their potential is unlimited. Boundless.
Boundless jerks around at the buzz of the intercom.
“Right!” Boundless takes a moment to glance down at themselves. Their jumpsuit is pastel pink with mint highlights. They have a utility belt, but their arms are bare, exposing the rose-coloured freckles stippled over their toned arms. Their moon boots are white with thick transparent soles.
Boundless laughs, because they look so cool and they’re so lucky to be made out of two amazing hero students. They can do this. They can do this!
“Time’s up. The exercise has begun.”
Boundless crouches low, calling all their power to their legs, and then jumps into the air. They quickly sail above the building and land effortlessly on the roof.
Gravity can’t touch them. No one can.
At lunch, Iida draws Izuku and Uraraka into a quiet hallway and then sinks into a formal bow.
“I was impressed by your fusion today,” Iida says, still facing the floor. “You’re both strong hero students, and I consider both of you to be my friends, even though we’ve only known each other for a few days. Please consider me a potential partner for fusions in the future! It would be an honour to fuse with either of you.”
Iida stays bent in that ninety-degree angle, even after he’s finished his speech. Izuku rocks back on his heels, hands bunched in the hem of his uniform shirt. His face feels red-hot.
Uraraka laughs. “No need to be so formal, Iida.”
Iida straightens out of his bow. “I didn’t want to be presumptuous and make either of you uncomfortable. You don’t have to accept—”
“Yes!” Izuku squeaks.
They both turn to look at him. He already feels like he’s swallowed a fistful of bees, like the fusion process has already begun and his body is unspooling, ready to reform into something greater.
Or, he thinks, maybe this buzzing feeling is just happiness.
“Please,” Izuku says, smiling so wide his cheeks hurt. “Let’s fuse together. All three of us.”
That afternoon, they borrow a small gym on the outer edges of campus. UA has so many training facilities. No one will notice if they use the space for an hour.
“I’m new at this,” Izuku says. “W-Why don’t you two go first?”
“If you’re sure,” Iida says. He turns to Uraraka, sinking into another formal bow. “Uraraka, will you do me the honour of fusing with me?”
“Of course! I’ve already said yes, haven’t I?”
Iida straightens up. “My parents always impressed upon the importance of asking first. Heroes often end up fusing in the heat of battle, and poor communication can lead to a disjointed fusion.”
Izuku scrambles for his backpack. He digs out his notebook and a pen, and sits down so he can take notes.
Uraraka and Iida fall into a loose waltz. Iida leads, but when Uraraka spins unexpectedly, pulling them off-course, he follows her easily. Their steps are a blend of ballroom and something more casual, following the winds of spontaneity.
A glow begins in their stomachs and travels up their chests. It eclipses their entire bodies. And then they’re fusing.
The fusion has choppy grey-blue hair and round pink glasses slipping down their nose. They’re a head taller than Izuku, their thick body roped with muscle. Their clothes don’t match UA’s dress code; their outfit looks more like a tux than a uniform.
There are aspects of the fusion that are clearly Uraraka or Iida, parts that are a clean mix of both of them, but there are also parts of the fusion that seem new. Something else entirely. It takes Izuku’s breath away. He scribbles furiously in his notebook.
They spot Izuku crouched by his bag and gasp. “Your mumbling is so cute!”
Izuku freezes. “P-Pardon?”
“I’m sorry, I should’ve introduced myself! I’m Apollo.” They stride forward, hauling Izuku to his feet. “It’s so good to see you, Izuku. You’re a great person. And an even greater friend.”
Izuku’s face is red-hot. He ducks down, retreating into his shirt collar like a turtle. “I-I’m not … I mean, you’re the fusion. You’re way cooler.”
“Nuh-uh! I’m a mix of two people’s opinions and thoughts. And I can feel all that admiration bubbling up inside me.” Apollo smiles, a fond little gesture that makes Izuku feel seen. “Ochako and Tenya really want to be your friend, you know.”
“Th-that’s good,” Izuku says. “I really want to be their friend too.”
He manages to fight through his embarrassment and jot down some notes about Apollo. Their personality is a surprise. They seem so much older and freer than Uraraka and Iida. Did the fusion bring out a different side of them? Or did their personalities collide and create something entirely new?
Their quirk appears to be an even split of them both—Iida’s speed combined with Uraraka’s antigravity. They’re lightweight and their engines propel them off the ground. With a gentle touch of their fingertips, they make Izuku float into the air.
Apollo would be amazing in a fight. They could sprint past their opponents, tapping them as they pass and sending them barrelling into the air. Izuku hopes he gets to see it one day.
Eventually, Apollo gets tired and Iida and Uraraka gently fall apart. They smile shyly at each other.
“You were amazing,” Izuku blurts.
“Thanks,” Uraraka says. “But now it’s your turn, Deku.”
Iida places Izuku’s right hand on his shoulder and then takes his left. Iida doesn’t comment on how sweaty Izuku’s palms are. They fall into a structured dance, circling the gym in a strict one-two-three, one-two-three step.
Izuku lets Iida lead. He’s too nervous to interfere with the dance like Uraraka had.
“Thank you for agreeing to this,” Iida says, turning them around so they can dance back towards Uraraka. “I wanted to fuse with you since I saw you save Uraraka against that zero-pointer.”
“Of course. You said you didn’t know the exam awarded rescue points, but that just makes your efforts even more heroic. You leap into danger because it’s the right thing, not because it’s something a hero should do.”
“I’ve wanted to fuse with you for a long time, too.” Izuku’s throat is tight. He can barely get the words out, though he doesn’t know if that’s the choking tears or the violent fizzing rising up his throat. “You’re going to be an amazing hero. I can already see it.”
Iida turns sharply and dips Izuku, and the buzzing light swallows them both.
Ingenious looks down. His uniform is different than the UA standard like Apollo’s had been, but it doesn’t look like formal wear; it looks like athletic gear, streamlined and made for speed. The engines in his legs are bulkier than Iida’s. Built to withstand immense power.
“How does it feel?” Uraraka asks, bouncing on her toes.
“Good,” Ingenious answers. Already, a barrage of half-formed ideas are pulsing in his mind, theories and battle strategies and training regimes. “Strong.”
“You look so cool,” Uraraka says, “like you could take down a building with just your legs. Just—blam! And then the whole thing is dust.”
Ingenious fiddles with his wire glasses, face heating. “Th-thank you. Although I’m not sure why we would want to bulldoze a building.”
“Deku did it just the other day!”
Ingenious grimaces, struck by a wave of disapproval and embarrassed stubbornness. It was reckless, but it had to be done.
“Well,” Ingenious begins, “it was dangerous and caused severe injury to Izuku, especially since he was playing the role of the hero, not the villain. But then again, if he was a pro hero and had to choose between destroying an abandoned building or letting a bomb detonate and cause mass casualties, then he made the correct decision. But this was only a class exercise and the only thing Izuku had to lose was pride—”
“Okay, okay!” Uraraka cuts in, backing up as she speaks. She gets halfway across the gym before she stops. “Enough nerding out. It’s my turn to join in the fun.”
Before Ingenious can ask what she means, Uraraka starts sprinting at them.
“W-wait!” Ingenious says, waving his hands in sharp chopping motions.
Uraraka twirls on her heel, laughing as she goes, and then leaps into his arms. He catches her around the knees, her arms looping around his neck, her laughter like bubbles in his ears.
The fusion happens so effortlessly that it takes them a moment to realise it’s even happened. None of them have ever fused with more than one person before, but they never thought it would feel like this—so full of love and potential.
Propulsion clenches their six hands. Electricity runs up their arms, the burn of One for All stirred up by a sudden fusion. There are engines in their arms as well as their legs. When they examine themselves in the tinted gym windows, they can see engines jutting out of their back, too.
Their outfit looks like a hero suit. Armour crisscrosses over their legs and torso, a tessellating pattern of pale pink, blue, and green, like the pastel dawn of a new morning. Their hair is a mess of black curls that catch the light, highlighting thin strands of rainbow colour.
They look strong and friendly and capable. A mash of all their best parts, welded together to form something new. Something strong.
Propulsion laughs, feeling lightheaded. Izuku, Tenya and Ochako hadn’t realised that when they fused they wouldn’t just combine their quirks; they would be combining their admiration and love too.
It’s a beautiful feeling. They never want it to end.
Izuku had gotten swept up in the magic of UA. The attack at USJ serves as the worst kind of reminder.
Because heroes aren’t the only ones that fuse in the heat of battle. Villains fuse, too.
Villains pour from that twisting black mouth, a great exodus that burns Izuku with fear. Adrenaline tastes like bile in his mouth.
They fuse in bursts. Clusters of villains lurch together, violent collisions that look nothing like his gentle dancing with Uraraka and Iida a few days ago. The fusions are larger than all of them, even Shoji.
That day teaches them about fear. That day gives rise to a new wave of fusions in Class 1-A. That day is the first day they really know what it’s like to be a hero.
Tsuyu corners him after class. Aizawa is at the front of the room, but he seems to ignore them in favour of slowly, painfully gathering up his notes with bandaged hands.
“During the USj attack, you were reckless,” Tsuyu says immediately. “You charged straight at villains that you had no hope of beating. If All Might and the other teachers hadn’t arrived, you would have been killed.”
Izuku stares down at his books. “Maybe. But I couldn’t just sit there when people were in danger. I had to do something.”
Tsuyu is quiet for a long minute. When Izuku looks up, she’s hunched in on herself, hands knotted over her sternum.
“I’m jealous,” she admits. “We almost died, but you were still so confident. You didn’t hesitate. You acted like a hero.”
Izuku stands up, chair screeching against the floor. “You acted like a hero too! Mineta and I would be dead if you weren’t there. And you didn’t fall apart when Shigaraki reached for you. I thought I was going to lose my mind, but you kept it together.”
Tears well up in her eyes. She crumbles in on herself, shaking her head. “But I wasn’t brave. I was—I was so scared.”
Izuku doesn’t think, he just steps forward and scoops her into a hug. Her face, pressed into his shoulder, is wet and quickly soaks through his shirt.
“I was scared too. I bet Aizawa-sensei was also really scared and I know All Might was. Being a hero is about keeping a level head and fighting even though you’re frightening. And you did that.
“You’re going to be great, Tsuyu. Your quirk is so versatile and it’s perfect for rescue scenarios. You’re calm and logical. You think things through instead of charging in blinding, like I do. I can’t wait until we’re pro heroes. I bet you’re going to save my life a hundred times over.”
Izuku doesn’t know where the words come from. But with Tsuyu shaking against his chest, her arms snaking around his waist to hold onto the back of his shirt, he just finds himself talking and unable to stop.
When Tsuyu pulls away, she looks steadier. She wipes her face with her sleeves.
“Midoriya,” she says, “fuse with me.”
Izuku trips backward, catching himself on a chair. “W-what?”
“If we’re ever in a situation like that again, I don’t want to feel so helpless and alone. And we’re friends, aren’t we?”
Izuku swallows hard. He can’t breathe, suddenly.
“Midoriya,” Tsuyu says, “don’t cry.”
“I’m not,” Izuku chokes. “I-I’m just. I’m just happy.”
A little over a week into the semester and he already has three friends. Four people to fuse with. It’s more than he imagined, more than he can ever put into words.
“Is that a yes?”
Strangled, Izuku says, “It’s a yes.”
Through his blurry vision, Izuku sees Aizawa slip out of the classroom as if he was never there.
The gym is still, dust motes floating in a wide beam of sunlight. The silence stirs up Izuku’s stomach.
“Will you two fuse with me after?” Tsuyu asks Iida and Uraraka. “I came here to fuse with Midoriya, but I think I’d like to fuse with you two as well.”
“I would be honoured!” Iida says.
Uraraka blushes pink, smiling so wide it looks like her cheeks hurt. “I’d love to.”
Tsuyu steps into the middle of the gym. Izuku follows after her and, without saying anything, their hands link together.
Neither of them lead. They move in a square, Izuku just managing to avoid stepping on her feet, until the rigid dance starts to break down and they loop around the gym in loose spins. Laughter bubbles up his throat. On impulse, he picks Tsuyu up and she braces her hands on his shoulders and then there’s a bright light and they’re fusing.
Dart is shorter than they would have liked. Their thick, dark hair is a mess of curls, and their skin is dusted with green freckles.
Uraraka has her camera out, already snapping pictures. “You look so cute! Powerful, but cute. What’s your name?”
“Because you’re fast,” Iida asks, “or because poisonous frogs are commonly referred to as dart frogs?”
They flex their four webbed hands. “Both, I think.”
“How does it feel?” Uraraka asks.
Dart flexes their webbed hands, feeling the strange flexibility and strength in their hands. “Right. It feels right.”
Izuku trains with All Might on early mornings and wrung-out afternoons, fitted between homework and hang-outs. His life has never been this busy before. It’s beautiful and terrifying and Mum still looks like she’s going to cry when he comes home smiling.
He keeps fusing with All Might. It becomes a little easier with each passing day, and Izuku can recall more about how One for All works when they unfuse, like he has started carrying some of Martys’s knowledge around with him.
It was only inevitable that someone would find out about Martys eventually.
Aizawa discovers Martys three weeks into the semester. The training facility is supposed to be empty, just Martys and the open, sprawling metropolis, but Aizawa strides in before he can leap into the air.
Martys freezes, One for All fizzling away like a snuffed flame. “A-Aizawa?”
“From the pale green hair and the towering height,” Aizawa says blankly, “I’d say you’re a fusion of All Might and Midoriya.”
“Uh. Yes, I am.”
Aizawa cocks his head to the side.“You should have mentioned that you had a child in the Hero Course, All Might.”
Martys unfuses with twin yelps. Izuku lays on the ground, dazed, but All Might bounces back up, hands waving frantically in the air.
“I don’t! I’m just mentoring young Midoriya. We don’t even look alike! Why would you assume I was his father?”
Izuku claps both hands over his red face. It’s not uncommon for people who aren’t close to fuse. For pro heroes, it’s normal to fuse with virtual strangers during emergencies.
But when people fuse in their spare time, there’s always a deeper connection. A trust, a shared affection as two souls meet and create a deeper bond between them.
“I didn’t say you were biologically related,” Aizawa says, “but if you’re fusing together regularly, which you clearly are, then he’s as good as your kid.”
All Might falters. Izuku peeks up at him through the slats of his fingers. All Might glances from Aizawa to him, an almost wistful expression on his face.
“Yeah,” All Might says, his voice soft, striking straight through Izuku’s heart. “I guess he is.”
“Touching,” Aizawa says dryly. “But I came here for a reason. You haven’t marked the last round of essays. The kids are getting impatient.”
Izuku remembers Kacchan almost clawing at his desk as he demanded their marks be returned to them. They had another essay due soon. Kacchan might have despised criticism, but he wasn’t an idiot. He knew how valuable academic feedback was.
All Might steps back, looking around the room as though cataloguing the exits. “Uh. Well, you see, I’ve been very busy—”
Aizawa glances at Izuku. “I can see that.”
“How are we supposed to start next week’s essays if we don’t know what we did wrong on the last one?” Izuku asks. All Might shrinks under his suddenly sharp stare. “Have you even started marking them?”
Aizawa smirks, a sadistic expression that would have filled Izuku with dread if it was directed towards him in class. “I’ll leave you at the mercy of your son. Finish those essays, All Might.”
(In the following months, Aizawa would come to regret teasing All Might.
He had never fused with a student before. None of his classes ever breached the cold distance Aizawa maintained.
But that year, with that class, something changed inside him. He fused with all twenty kids, one after the other, like dominoes falling into place. And it was like a piece of his soul was returning to him each time.
Hizashi and Nemuri tease him about it ruthlessly. All Might just smiles knowingly at him from across the staff room.
And Aizawa couldn’t even argue with them. They’re his kids. He’ll do anything for them.
And he wouldn’t have it any other way.)
Izuku starts fusing with the rest of the class.
A few weeks into the semester, during a relaxed training session, Ashido tracks him down and pulls them into a hip-hop routine that ends with Izuku getting thrown into the air like a pizza and caught in her glowing arms.
He fuses with Kaminari during class, and their fusion, Tenectricity, short-circuits the entire arena. It takes almost twenty minutes for the lights to come back on.
Another day, when their class is sorted into pairs and all ten couples are pitted against each other, his fusion with Momo, Stratagem, cooks up a plan so convoluted and strange that it lands them in Principal Nezu’s office. He congratulates them on their decimating win and offers them private lessons on strategy. All Might turns white when Izuku tells him about it that afternoon.
Izuku always thought fusion was something for other people. Not him. Not Deku.
Sometimes, it feels like a dream that’s going to end. But for now, Izuku embraces every new fusion, every new friend he makes along the way, and lets himself relearn what it’s like to be happy.
Fusions aren’t allowed at the sports festival. The day is for demonstrating their individual abilities and kickstarting their careers.
But then, after receiving several declarations of war, Izuku doesn’t think anyone would agree to fuse with him even if it was allowed.
But it still stings, standing so close to Tokoyami and Uraraka and knowing he can’t fuse with them. Izuku spent years being unable to fuse with anyone. He hadn’t realised how much he would miss it.
In a few days, he can seek his friends out, fuse with them, and rid himself of this itchy, despondent feeling.
But then, he reminds himself, not everyone has that option.
Todoroki cuts such a lonely figure when he pulls Izuku into a deserted corridor. He says that he doesn’t need fusions or his fire, and he’ll become Number One on his own, with only his ice.
That’s bullshit, Izuku thinks, One for All burning in his hands. That’s bullshit. And he’s going to make Todoroki see that.
A week after the sports festival, Todoroki seeks him out. His stare pins Izuku in place, makes him forget about the world around him.
“You fuse with our classmates regularly,” Todoroki says.
Izuku blinks. “Yeah, I guess.”
“You have All Might’s power.”
“I’m not—” Izuku cuts himself off. The love child theory threw him, but he can’t deny Todoroki’s phrasing. “It’s not what you think, Todoroki.”
“Your power is similar to All Might’s,” Todoroki says again. “But you don’t share his aversion to fusing.”
“All Might doesn’t hate fusing. The press just thinks he does because he doesn’t do it publicly.”
“He does fuse then? With who?”
Izuku considers lying. But Todoroki looks like he did in that shadowed hallway, stiff and blank, like he’s waiting for a blow.
He’s never seen Todoroki fuse with their classmates. And if his childhood was as violent and isolated as he said it was …
“I fuse with him sometimes,” Izuku says, trying to sound casual. “H-he’s been helping me figure out how to use my quirk without hurting myself.”
“It’s clearly not working.”
Izuku winces. “Yeah, it’s slow going. It’s hard to teach me when we’re an us. As a fusion, his knowledge is my knowledge and vice versa. But it becomes foggy when we unfuse.”
“Then why do you do it?”
“When we fuse ...” Izuku fumbles to describe the joy and love and potential of being a fusion. It’s something that surpasses words. “It’s like nothing I’ve ever felt before. As a fusion, you’re more. Not because you’re less as an individual, but because you’re joined with someone else who’s amazing and powerful and kind. You can feel how much love and pain they have inside them. Fusion is … it’s opening yourself up to someone else and being loved, down to your very core.”
Izuku closes his mouth with a click of teeth. He said too much. But he doesn’t regret it, just like he doesn’t regret tearing himself apart during the sports festival.
“I’ve never fused with anyone before,” Todoroki says.
“I thought so,” Izuku says gently.
“It was my father’s choice. He wants me to be strong enough on my own. If All Might can be Number One without using fusion to get ahead, then I need to do the same.”
Endeavour fuses all the time. He keeps certain sidekicks on retention simply because their quirks, combined with his, make powerful fusions.
But, apparently, his own child can’t do the same. Not even outside the battlefield.
“Fusion isn’t weakness,” Izuku says. “It’s not necessarily strength either. It doesn’t have to be something you weaponise.” Izuku flaps a hand in the air, struggling to find words to describe something indescribable. “It’s—it’s an experience.”
“An experience,” Todoroki echoes flatly.
“I don’t just fuse with All Might because he’s training me. I do it because he’s special to me.” Todoroki studies him, his eyes shadowed. Izuku takes a step forward and smiles. “I can show you, if you want.”
“I don’t want to use my quirk like that,” Todoroki says. “Not yet.”
“We don’t have to use our quirks at all. We can fuse outside of class. Just you and me.”
And, maybe, he can coax Todoroki into that sunlit gym where he still meets up with Uraraka, Iida and Tsuyu. He doesn’t know if any of them have ever spoken with Todoroki before, but he knows they would welcome him with open arms.
“Just you and me,” Todoroki repeats. “Okay.”
At lunchtime, Todoroki and Izuku move the desks back. The classroom is still cramped.
Todoroki’s shoulders are tight under his hands. Izuku pulls on a bright smile and takes the lead, trying to show Todoroki that he’s safe here.
It’s okay, Izuku tries to say with each steady turn of their bodies. You’re okay.
Worrying about Todoroki makes it easy to ignore his own anxiety. He feels less self-conscious when he’s fixated on someone else’s stress.
They twirl in tight circles around the front of the empty classroom. Todoroki remains stiff. Time stretches on until Izuku begins to worry that lunch will end before they’re able to fuse.
“I’m sorry,” Todoroki says abruptly.
“Do you want to hear about how I fused with Iida?” Izuku asks. “He was so formal. I felt like he was asking Uraraka and I to marry him or something.”
Izuku talks until Todoroki starts to forget that Izuku’s hands are on his shoulders and their bodies are inches apart. Their movements fall into a rhythm. He tells Todoroki about how nervous All Might was to teach their class, and how Aizawa was the first person to accuse him of being All Might’s son, and how All Might still gets red in the face when he remembers Aizawa’s smirk when he said that. He talks about lunch. Upcoming essays. His thoughts on Todoroki’s costume.
He doesn’t think Todoroki even notices when the fizzing starts; Izuku has mistaken it for nervous joy before. But Izuku has fused dozens of times before, and so when the soft buzzing starts deep in his stomach, he knows what’s coming.
It takes a while for it to creep up his ribs and into his face, a slow and gradual submersion that makes Izuku bite down a grin.
He holds Todoroki tighter and spins them around a little faster. Todoroki turns on his heel so that he’s leading, hands firm on Izuku’s waist, almost knocking them into the teacher’s desk as they sweep backwards, pivoting tightly at the last minute.
They move faster and faster. Izuku is sure they’re going to knock right into the desks and break something, and then they twirl one last time, a sharp, almost too-fast gesture that makes Izuku feel dizzy.
Monsoon twirls to a stop. The only sound in the classroom is his quiet panting. His ears ring.
Monsoon looks down. And finds he can’t stop staring at his hands.
Two hands, tanned and spotted with white freckles, like freshly fallen snow. Spidery scars run up his wrists. It doesn’t look violent like Izuku’s scars do, or faded and ugly like Shouto’s. Instead, they twist over his knuckles like vines, like a stream snaking down a hill.
Being a fusion is quiet. He doesn’t feel like a weapon, like Shouto had thought he would. And there is no sudden, overwhelming rush of joy and relief like there had been when Izuku had fused with All Might. This is gentle. It’s safe. It’s falling into bed after a long day.
Monsoon is so distracted that he doesn’t notice the bell ringing at the end of lunch.
The door opens. He blinks at the classmates standing in the threshold, gaping at him.
Uraraka shoves through the crowd. “Deku, you didn’t tell us you were fusing with someone new!”
Monsoon scratches at the back of his head. His hair feels thick and soft under his fingers. “Sorry.”
“That’s Midoriya and Todoroki, right?” Kaminari asks, eyes wide. “You look so good, dude! What’s your name?”
Kaminari sighs. “Even your name is cool.”
Hagakure and Ashido push past Kaminari, examining Monsoon carefully.
“I’m so jealous,” Hagakure says. “I’ve never seen Todoroki fuse with someone before! No fair.”
Kaminari goes very pale. “Oh, god. Are you two going to start fusing in class?”
Everyone stops and considers Monsoon with new eyes. Sero looks faintly ill, while Ojirou looks like his fight or flight instinct has just been triggered.
“Midoriya is the only guy in the Top 3 that fuses regularly,” Sero says. “If we’re going to get two overpowered people fusing ...”
“Have you used your quirk yet?” Ashido says. “You must be so OP. Midoriya and Todoroki’s quirks would dominate. So cool.”
Monsoon blinks down at them. His quirk? Why does that matter? His quirk is something violent that rips up the earth. It doesn’t belong here. Monsoon doesn’t exist to fight, though he will if his friends are in danger. But Monsoon isn’t in danger now. He’s surrounded by his classmates, floating in the still-new feeling of being safe.
“Cool?” Ojirou repeats. “Ashido, we’re going to die.”
Kaminari giggles. It sounds vaguely hysterical. “Imagine if Bakugou ever gets over his hatred of fusions.”
“A Bakugou, Midoriya, Todoroki fusion would be strong enough to kill god,” Sero says.
“We’re going to die,” Ojirou says again.
“It’s okay,” Monsoon says, a tight feeling in his stomach that he doesn’t understand. “I don’t think Bakugou would ever fuse with us.”
At the training camp, the Wild Wild Pussy Cats dance around each other, a synchronised twirl-step routine that Izuku has seen a hundred times on TV. Their fusion towers over the students, easily larger than a two-storey house. It’s breath-taking.
Fusions are everywhere at camp. After all, fusions are another tool, another way for heroes to fight. Another thing they have to master.
Kirishima and Tetsutetsu fuse into a loud, immovable wall, while Monoma is still trying and failing to fuse with his classmates. Most of Class 1-A has mastered fusing, but a few members of the Wild Wild Pussy Cats try and talk to Kacchan about fusing. He always blows them off. He still equates fusing with losing.
But in the end, their class’s proficiency in fusion saves their life. When the League of Villains attacks, the students fuse with whoever is closest. They know they’re stronger together.
When the villains escape and Izuku feels numb with shock and blood loss, he can’t help but wonder if Kacchan’s refusal to fuse is the reason why he was taken.
For a moment, as they’re rocketing across the sky and Kirishima is reaching for Kacchan’s hand, Izuku thinks they’re going to fuse. They don’t. But the thought still lingers in the back of his mind, growing steadily.
The night they move into the dorms, Kacchan disappears into his room. They all quietly decide to give him space.
But later in the evening, after Room King has ended and Tsuyu has cried herself out, Kirishima slips away. No one comments. But Izuku thinks he knows where Kirishima has gone anyway.
The strange, anxious energy that’s befallen the class after Kamino Ward follows them into their first training session. Izuku can feel his classmates staring at All Might. It makes him bristle, but then again, he’s fixated on All Might’s emancipated form too. You’re next echoes through his head like a death chime.
The stifling atmosphere is broken when Kacchan snarls, “You think that’s a special move, Pikachu? No fucking way. Kirishima, get over here!”
Kirishima springs up behind Kaminari and Sero. “Are you sure, man? I don’t want to push you if you’re not ready—”
“Shut up.” Kacchan holds out an arm. He doesn’t look embarrassed, exactly, but he has trouble meeting Kirishima’s gaze. “You heard what I said last night.”
“Okay,” Kirishima says, surprisingly soft. “I trust you.”
Kirishima dashes around his friends and takes a running leap at Kacchan, who catches him with ease. Kirishima’s legs are braced against Kacchan’s gauntlets like he’s going to rocket him up into the air, but then Kacchan turns and hauls Kirishima into a reckless spin and they start glowing—
Their classmates scream with excitement as the fusion forms. Light ebbs away to reveal a sharp-toothed smile.
“Dude,” Sero says.
“DUDE,” Kaminari says.
“Fuck YES,” Ashido says. She already has her phone out to take pictures, despite Aizawa’s strict rule about not having their devices while training. He’s definitely going to confiscate it before class is up.
The fusion turns that cocksure grin in their direction. He looks so smug, so challenging, and yet so thrilled to see his friends. It’s a perfect mix of Kirishima and Kacchan—from the heavy armour covering him to the ombre hair (white-blond at the roots, blood-red at the spiky ends) tumbling down their shoulders.
Izuku has seen hundreds of fusions before, so why is he so unbalanced at seeing this fusion?
“Hey, guys. I’m Break-Through.” He slams his plated hands together. It sparks, like a hammer forging metal. “What’d you think?”
Everyone starts yelling their praise, and Break-Through laughs and promises to take them all on.
“Wait,” Ashido says. “If Bakugou is fusing now, does this mean we’re going to get Bakusquad fusion?”
“Yes,” Kaminari says. “Bakugou, dude, it’s not the same without you.”
“I know,” Break-Through says, and it’s unclear whether the words come from Bakugou’s arrogance or Kirishima’s honesty.
Ojirou crests one of the training centre’s rocky cliffs to see what is causing the noise. He pales at the sight of Break-Through. “Oh, fuck.”
“Indeed,” Tokoyami says on the other side of Izuku.
“What’s wrong?” Izuku asks.
Ojirou grimaces. “Bakugou is fusing now.”
“He’s tough enough to face in class as is,” Satou says, looking a strange mix of impressed and terrified. “And fusions are always a lot stronger than individual people. He’s going to be a nightmare.”
Ojirou turns to him. “Midoriya, you’re a good person, right?”
“Um,” Izuku says. “I try to be?”
“Monsoon has already kicked all of our asses,” Ojirou says, “even though he said he was a pacifist. You can’t let a fusion with you, Todoroki and Bakugou exist. Not during training sessions, anyway.”
“Um,” Izuku says again.
“Midoriya,” Ojirou says seriously. “We would die.”
Izuku laughs awkwardly. “I really don’t think you have anything to worry about.” His gaze flicks back to Break-Through, laughing and showing off for his friends. “Kacchan would never fuse with me.”
Kirishima had broken through a decades-old barrier. After that first week after Kamino Ward, when Kacchan blushes and snaps at anyone that tries to talk to him about fusing, he starts warming up to their classmates.
A full eight days after school resumes, Kacchan fuses with Ashido. Their stocky fusion has pastel-pink skin and a shock of blond hair. Their quirk destroys several warehouses, including a replica petrol station that would’ve killed dozens of civilians if this was a real fight. Aizawa calls an abrupt end to the exercise, after that.
After Ashido, Kacchan fuses with Uraraka. Then comes Sero and Kaminari and even Momo. Izuku has started to feel sick every time he glances at Kacchan and sees him surrounded by people, their classmates smiling and hanging off him without any fear of Kacchan blowing them up for the slightest transgression.
If Kacchan feels Izuku staring, he doesn’t say anything or even look back. It makes the nausea in his stomach bloom into a proper ache. He would visit Recovery Girl if he didn’t recognise the pain as anxiety.
Their fight doesn’t make anything clearer. Kacchan is hurting, and Izuku had no idea, and that eats at him. He thought he knew Kacchan. Their lives are interwoven in a way that goes beyond words, but there’s so much misunderstanding and resentment between them. So many tangled emotions Izuku keeps choking on.
And in the end, Izuku isn’t even sure why he brings it up. Watching Kacchan vacuum around the couches, looking domestic and sullen in house-slippers and sweats, something snaps inside him.
Izuku blurts, “Why did you fuse with Kirishima?”
Kacchan blinks at him. “What?”
“You’ve always said you were above fusing,” Izuku says. “And then suddenly Break-Through is showing off in class. I don’t get it.”
“We weren’t showing off—”
Izuku switches off his vacuum. He doesn’t want to fight with Kacchan again. They’re already on thin ice with Aizawa. But he refuses to be that skinny, frightened kid that tiptoes around Kacchan.
And after everything, he deserves the truth.
“You’ve fused with six of our classmates now. Six. Where the hell did that come from?”
Kacchan switches off his own vacuum. He kicks at it with no real force, and admits, “It didn’t help All Might in the end, did it? He refused to fuse with anyone—he didn’t have anyone to fuse with. And what happened?”
Izuku thinks about All Might’s tall, malnourished figure, bloody and triumphant against a backdrop of smoke.
“He had me to fuse with,” Izuku says, voice small.
“You were too busy saving me!”
“You needed me.” Izuku had ached to be there with All Might, fighting by his side, but he wasn’t strong enough. He would have just distracted him. And he had to save Kacchan, even if it lost him his place at UA, even if it meant Kacchan would resent him forever.
“I know!” Kacchan shoves a hand through his hair, teeth gritted. “I fucking know, okay? I wasn’t strong enough to save myself, so you and the rest of those losers had to put yourself in danger. And All Might—”
Kacchan cuts himself off, swallowing hard. “I wasn’t strong enough,” he says again. “But All Might wasn’t strong enough either. We were both just—alone.”
“That’s why heroes work in teams,” Izuku says, thinking of Iida’s arm against his chest to keep him from sprinting into danger, of Kirishima’s steady hand against Kacchan’s, wrenching him through the air.
Kacchan blows out an unsteady breath. “So maybe fusions aren’t bullshit. I don’t know. But I’m not going to make the same mistakes as I did before.”
They stare at each other across the living room. Izuku thought fusions started with a bow or maybe with clasped hands, but he realises that that’s not right; fusions always start with this mutual feeling of being seen.
“I know,” Kacchan begins, voice rough, “that I don’t deserve—I was a fucking dickhead and you didn’t deserve any of it and I-I can’t ask you to—”
“Yes,” Izuku blurts.
Izuku’s heart is beating hard in his chest. “I’ll fuse with you, o-okay?”
Kacchan looks just as caught, just as scared, and his voice shakes as he says, “Okay.”
They head to the courtyard outside the dorms. Everyone is in class. There’s no one to see how awkwardly they stand in front of each other, how the silence lingers for too long, choking them both.
“Should we dance?” Kacchan asks.
Izuku thinks about being four years old, stumbling around his bedroom with Kacchan’s hands in his, almost tripping on the guest futon. No. That’s not what he wants.
Izuku holds out a hand.
Kacchan hesitates. Stares at Izuku’s scarred hand as if he thinks it’ll bite him. And then he takes it.
Kacchan’s hand is sweaty and too-hot. Izuku flexes his fingers and feels Kacchan’s hand twitch against his palm.
“I’m sorry,” Kacchan says, so quietly that Izuku almost thinks he imagines it. “I know that’s not enough.”
“It’s not,” Izuku agrees. “But it’s going to be okay. One day.”
“Should’ve known I could never get rid of you.”
Izuku’s hand tightens in Kacchan’s. His smile sharpens, turns challenging. “Never.”
Kacchan’s lips twitch, and Izuku swears he sees a smile there, and then the buzzing in their stomachs rises to encompass them both.
The fusion doesn’t last a full minute.
In that moment, when Izuku is one with Kacchan for the second time in his life, he feels warm and shivery, like he’s pushed himself too hard during training. But Cain also feels strong. Like, if he had to, he could take on the world and win.
Cain is exposed, too. It’s a strange juxtaposition, a mishmash of emotions too big to fit into one body, and it makes him feel dizzy with the force of it.
(Later, Izuku will look back on that moment and wonder where that intense feeling of vulnerability came from. Were those Izuku’s emotions or Kacchan’s? Or was it some amalgamation of them both, a sensation bubbling up from the place where their souls touched?)
Cain can see his reflection in the window. He’s a disjointed fusion. His hair is split like Todoroki’s, one half blond and the other curly green, rather than a healthy blend. Freckles blot his skin like small scars. It reminds him of cigarette burns. And his face is a mess. His bones are all wrong, warping his features, and his face is twisted up. That expression—it hurts.
“Don’t look like that,” Cain says, voice warbled. “I’m not doing anything wrong. But you’re—we’re not—everything is fine—”
They’re ripped apart violently. Izuku twitches against the pavement, watching Kacchan paw at his chest, panting heavily. Kacchan looks up. Their eyes catch.
Did you feel it? Izuku wonders. Before our issues overwhelmed us and Cain fell apart—did you feel how strong we were, how steady, how alive?
Kacchan looks away. “I heard you’ve been fusing with All Might. What’s that like?”
“It’s hard to explain,” Izuku says. “It’s a relief, I guess. Like getting lost and turning a corner and suddenly finding your way home.”
Kacchan nods, a faraway look in his eyes. His elbows are propped on his knees. They haven’t done anything today aside from clean and dredge up the past, but Kacchan looks exhausted.
Izuku wets his lips. “What’s it like fusing with Kirishima?”
“It’s a relief too,” Kacchan says, “but it’s also ... I don’t know. It’s calming and exciting at the same time. Like finally getting to be comfortable in your own skin.”
“I’m glad,” Izuku says softly, and finds he means it, even though he found it hard to look at Break-Through in class. He’s glad Kacchan has that.
Kacchan focuses intently on his scuffed shoes. “And you’ve been fusing with those nerds after school, right?”
“Yeah. You’re not exactly subtle.”
Izuku picks at a loose thread in his shorts. “It was just Uraraka and Iida, at first. But then Tsuyu and Todoroki started coming. Um, I think we might invite Aoyama soon? It’s fun.”
Kacchan is quiet for a long time. Long enough that Izuku considers picking himself off the ground and going back inside, before Aizawa catches them slacking on chores. Then, Kacchan jerks his head, a nod, and says, “I’m glad too.”
They exchange tight smiles over their knees. It looks nothing like Cain’s hurt, vulnerable expression, reflected back at them through the tinted windows.
Izuku isn’t ready to forgive Kacchan—or, well, that’s not true. Izuku thinks Kacchan isn’t ready to forgive himself. And Izuku still doesn’t know what to do with the weight balled up in his chest, the past and the present tangling together and pressing on his lungs.
But it’s a start. It’s progress. It’s a promise of a better tomorrow.
And that’s more than he could have ever imagined.
They don’t mean to fuse.
They’re gathered in Izuku’s room, textbooks sprawled around them. Despite Iida’s growing stress, no one is studying.
Tsuyu and Uraraka lay together on his bed. Tsuyu’s long hair spills over the mattress in a green waterfall. Iida, sat against the bed frame, placidly let’s Uraraka’s arms flop over his shoulders, even though she takes far too much delight in messing with him every time he starts nagging them about studying.
Whenever Iida loudly reminds them of upcoming exams, Uraraka slaps her hands over his mouth, or steals his glasses, or makes him float a few inches above the carpet, until Iida is laughing helplessly, batting at her hands, trying to choke out his half-hearted lecture.
Izuku sits against his desk. Iida’s legs press into his every time Uraraka digs her fingers into one of Iida’s ticklish spots.
Todoroki is laid out beside Izuku, head pillowed on his thighs. Izuku is ready to defend him in case Iida flails too much and kicks out towards Todoroki’s face.
Their textbooks have long since been abandoned. Tsuyu has her phone out, filming Uraraka and Iida.
They don’t mean to fuse. There’s no dancing, no hand-holding, no humming the same tune. No traditional fusion-trigger.
Izuku’s curtains are open and a wide sunbeam falls over them. Dust modes swirl in the air. Iida’s laughter reaches a crescendo, and Izuku feels so warm that he could melt, contentness a physical buzz beneath his breastbone.
And then they’re glowing.
Ascent blinks open two sets of eyes and takes in the room anew. It’s much smaller from this angle. Or rather, they are so much bigger. If they raise their arms, their fingers would touch the roof.
They look down. They have six arms and four thick legs. Their body is a swirl of rainbow, colours rolling over each other like a marble painting. Over their shoulder, a blotch of red bleeds into pink and then fades into white. Their toned stomach is exposed beneath their crop top, and they can see a streak of cobalt blue bleeding into a sea of green tones.
It’s normal for young fusions to be a clumsy mess of colours, and accidental fusions aren’t as cohesive as planned ones. But, for some reason, Ascent feels like something is missing. The red clashes too abruptly with the cool-toned colours. They needed something else, some balance …
The door opens. Ascent blinks, long rainbow hair falling into their eyes. Shinsou stares back at them. His books are slipping out of his arms.
“Hello,” Ascent says, holding out a hand. They’re too big to fit through the doorway, but they want their friend to come in, to get closer, to let them be close to him.
Shinsou stumbles back. “You’re ...”
“Wait,” Ascent says, but Shinsou takes another step back.
“I saw Midoriya’s invite to study in the group chat and I just assumed that—sorry. I’ll go. Sorry.”
Shinsou turns on his heel and runs back down the hallway, ignoring Ascent’s cries for him to come back.
The fusion falls apart. Izuku is already up and running before the static prickle of a broken fusion can fade.
He finds Shinsou on the roof, looking out over campus. “Go away, Midoriya. I don’t want to study anymore.”
“That’s not why I’m here,” Izuku says, joining Shinsou by the railing. “You ran away pretty quickly.”
Shinsou’s shoulders hunch around his ears. “I didn’t meant to intrude.”
“You weren’t intruding. You’re our friend. We were happy to see you.” Izuku scrubs a hand through his curls, laughing, remembering the feel of Apollo ruffling his hair with such abject awe at how soft it was. “Our group tends to be pretty excited to see our friends when we’re fused. You probably would’ve gotten fussed over.”
“You don’t need to do that.”
Izuku blinks. “Do what?”
“Pretend,” Shinsou says, braced against the railing. “You don’t need to … Look, I get it. I’ve only been a part of the class for a few weeks.”
“I’m not pretending! Shinsou, we really did want you there.” And then, Izuku says softly, “We would have fused with you too.”
Shinsou flinches. He adopts that old defensive glare Izuku has become immune to. “I said, don’t.”
“I want to fuse with you,” Izuku says, like a challenge. “You don’t have to if you don’t want to, but you’re my friend. I’d enjoy it and I think we’d make an awesome fusion.”
“You? But your All Might’s—I mean, your quirk is almost perfect, golden boy. Why would you want to pair it with mine?”
Perfect? Izuku wonders if Shinsou has forgotten how many bones Izuku had broken at the sports festival. He shakes his head. “An offensive strength quirk with an uncommon psychic quirk? Shinsou, we’d be unstoppable.”
Shinsou sighs and pushes away from the railing. “You’re not going to let this go, are you?”
“Fine. Let’s get this over with.”
On the walk across campus, Shinsou begins to lag.
“I’ve never,” he begins, not looking at Izuku. “I’ve never fused with anyone before.”
“That’s okay,” Izuku says, smiling. “I hadn’t fused with a friend before this year either.”
Shinsou barks out a laugh. “You? Really?”
“Well, I fused with Kacchan when I was four. It wasn’t … It didn’t go well. Didn’t leave either of us with much love for fusing.” Izuku scratches the back of his head, sheepish. “And I guess I also fused with All Might too, b-but that doesn’t count! We’re talking about friends! Uraraka was the first friend I fused with, a few weeks into the semester. She and Iida had to teach me.”
“You fuse with All Might?” Shinsou laughs, shaking his head. “Todoroki was right, I guess.”
“What does that mean?” Izuku demands.
“Nothing,” Shinsou says, picking up his pace. “Come on, sensei. Teach me about fusion.”
Izuku talks as they walk. About fusing methods, and quirk match-ups, and famous hero fusions. About how stiff and formal Iida had been during their first dance, as nervous as Izuku even though he had been fusing for most of his life. About All Might.
They go to the same gym where Izuku first fused with Iida and Uraraka. It feels strange to be the one coaxing someone else into a dance, rather than the other way around.
Izuku loves fusing, but he will never have an elaborate fusion dance like the Wild Wild Pussycats. When he fuses with classmates with elaborate dance-styles like Ashido or Aoyama, he lets them dance around him, guide him, spin him, throw him in the air (or, alternatively, throw them in the air). But that will never be his natural style.
“Okay,” Izuku says, holding his hands out, the way Uraraka had held her hands out to him. “Let’s start like this.”
Shinsou reluctantly slots their palms together. His skin is cold and clammy, like he’s been standing out in the snow.
“Follow my lead,” Izuku says.
He sways from side to side and Shinsou matches his steps. After a few minutes of painfully awkward silence, no bubbles rise in his stomach. He just feels uncomfortable.
He tries leading Shinsou around the gym in loose circles, their hands still clasped and swaying to some nonexistent beat. That makes him feel worse.
“It’s not working,” Shinsou says after a few more minutes. “We’re not compatible, Midoriya.”
“That’s not it,” Izuku says, pulling Shinsou into a desperate spin that almost topples them both. “Sorry. I have no rhythm.”
Shinsou pulls his hands away and stuffs them in his pockets. “Whatever. You tried, I guess.”
“I’m not giving up.”
“Don’t waste your time, Midoriya. Neither of us have any dancing skill and we’re not close enough to fuse through proximity.” Shinsou musters up a smile, one of the first Izuku has seen on him, and that somehow makes him feel worse. “It’s okay, really. I’m happy you tried.”
“Wait,” Izuku says again, thinking hard. “Let’s try a different approach. Neither of us know anything about dancing, but we do know a lot about fighting. Let’s spar.”
“I don’t think hitting each other will make us bond.”
“It’s about getting in sync. We don’t have to try and hurt each other; we just have to move together. Get our minds and bodies on the same page.” Izuku rearranges them until they’re a few feet apart, and drops into a loose fighting stance. “Okay. Try and hit me. But do it at half your usual speed and don’t try any dirty tricks.”
“You and Uraraka are the dirtiest fighters in our year,” Shinsou grumbles, but obligingly throws a slow punch.
Izuku shoves his arm back, their wrists clashing together like swords. “Again.”
Shinsou pushes him back gradually, and Izuku lets him take the lead. They throw slow attacks, blocks that feel so gentle they are almost like practise holds. It feels like they are demonstrating a fight for an audience, natural and yet almost choreographed. Like dancing.
A telltale buzz begins to froth up in his chest. Izuku bites back a grin. Their spar increases in speed, becoming more like a real fight. They keep gaining momentum until they are grappling on the gym floor and glowing, their bodies buzzing with energy.
The shock of fusion almost splits them apart. Izuku is only just able to keep them together.
Prevail looks down at himself. He seems to be an average height for a teenage boy, though less stocky than he had hoped. He’s wearing a comfortable black hoodie and matching sweatpants. It almost feels like pyjamas until he looks closer and sees all the hidden pockets, the utility belt tucked under the downy-lining of his sweatshirt. He has handcuffs, notebooks, and tape recorders. Perfect for stealth work.
He’s wearing fingerless gloves too. When Prevail pulls back one sleeve, he sees that the glove extends up and past his elbow. An arm brace, like the ones Izuku wears.
Versatile, Izuku had called them.
Prevail might have the self doubt of two teenage boys swirling inside him but in that moment, staring down at their plain costume, he feels almost giddy with excitement.
It’s lunchtime. Hero Training finished ten minutes ago, giving them just enough time to peel themselves off the asphalt, eat the healing gummies All Might had squirrelled away for class, before washing and changing up.
In the end, they didn’t make it to the cafeteria.
On the way to the main building, Shinsou says, “Fuck this,” and then collapses onto a freshly-mowed patch of grass.
“Oh my god, he’s dead,” Kaminari says.
“Is he okay?” Sero asks.
Kirishima turns on his heel. “Yeah, he’s fine. But he’s dead.”
“Worm,” Jirou agrees and then flops onto the grass.
Ashido and Hagakure follow her down, groaning about their hurting joints, even after all the gummies All Might had given them. They hadn’t had time to fuse before Bakugou and Uraraka, and had almost been knocked out in the ensuing attack.
“We have limited time before lunch is over!” Iida chops his hands in front of Jirou, who doesn’t even bother opening her eyes before flipping him off.
Kaminari sucks in a deep breath. “CUDDLE PILE.”
Jirou’s eyes fly open. “Don’t you dare—”
Kaminari lands on top of her. They roll away in a tangle of limbs and curses. Kirishima and Sero jump onto the grass after them, laughing and staying far enough away to avoid Jirou’s swinging fists.
“Careful you don’t accidentally fuse!” Iida says. “We don’t have time for—”
Iida is cut off as Uraraka tackles him onto the grass. Tsuyu and Todoroki follow them down much more delicately, and Iida sighs, resigned to laying sandwiched between his friends.
“Relax,” Tsuyu says. “We have Present Mic after lunch. He doesn’t mind if we’re late.”
The rest of the class ends up sprawled on the lawn, complaining about their tired muscles. Bakugou has gotten entangled in Jirou and Kaminari’s fight, roping Kirishima in, if only to try and defuse the situation. Shinsou’s head lolls on Izuku’s shoulder. He looks ready to fall asleep.
“This isn’t normal, you know,” Shinsou grumbles.
Izuku blinks lazily at him. His whole body feels loose, ready to fuse with any of the nineteen people sprawled out around him.
“What do you mean?”
“This class isn’t normal. People aren’t this close. They don’t fuse as easily as you all do.”
Iida sits up on the other side of Shinsou. “It’s true that people don’t commonly fuse in groups like we do. But most people haven’t been through what we have.”
“We haven’t seen all the group-fusions yet,” Uraraka says. “I’m keeping a list! We still need to do an all-girls fusion.”
“Oh, god,” Ojirou says, tucked against Kouda. “Imagine a Bakugou, Midoriya and Todoroki fusion.”
“They would level a city,” Ashido says with glee.
“The Bakusquad fusion is still the best multi-fusion,” Sero says, and Ashido laughs and high-fives him.
Shinsou shakes his head, looking tired and horrified and fond all at once. “You’re going to take the world by storm.”
Uraraka reaches across Iida and pokes Shinsou gently in the ribs. “We’re going to take the world by storm.”
Izuku settles down in the grass. His whole body aches from training, but if he had to, if his nineteen friends scooped him up into a dance right now, he thinks he could fuse at the drop of a hat.
“Yeah,” Izuku says, smiling softly. “They’re not going to know what hit them.”