The loud twang of a biwa rang through the usual silence of the Infinity Fortress and Nobu opened their eyes. Muzan loomed over them with a deadly glint in his crimson eyes, mouth set in a small frown.
"They're dead." They hummed softly and sat up from where they were lying on the futon to look up at him with a tilt of their head. His mouth twisted further and he glided past them to the desk in the back of the room. Papers and books flying through the air as he swept them off in a fit of anger.
"I left one alive: Lower Moon One," He hissed, nails digging into the wood, "But they're all so weak."
Coming up behind him, Nobu wrapped their arms around his torso gently, resting their cheek on his back. The demon lord made no move to stop them as their hands drifted upwards to touch his messy bun.
"You're messing up your hair," They murmured softly. The shorter demon tugged at the hairpiece and let his dark locks fall to his shoulders in loose waves. They guided him to the futon and he sat down in one fluid movement, clawed fingers drumming incessantly on the floor. "Let me fix it."
Combing through his dark locks, they hummed softly as he glowered at the wall. Muzan was furious, absolutely so, but the feeling of petite fingers running through his hair and the soothing hums eventually made the fuming woman relax. The tension in his shoulders faded away and he tilted his head back slightly to look at the other.
"You've always liked this form, haven't you?"
It was less of a question and more of a statement. The first year after he had stolen them from their life as a human, locking them deep within the Fortress, they'd fought tooth and nail against his every order. Most nights he'd have them tied up and pinned underneath his body as he pleasured himself, the younger demon somehow still flipping the tables and pulling themselves on top. The first time he'd appeared before them, painted lips twisted into a sinister smile and long haired pinned up in perfection, the look on their face was on he'd cherish for centuries.
Nobu’s attitude had completely changed that night.
They didn't reply to his comment, red gaze unmoving from where they were putting the last finishing touches on his hair. He pulled out of their grasp as soon as their hold slackened and turned to face them, a single finger tilting their chin up.
Muzan sunk his teeth into the inside of his cheek, blood pooling into his mouth, and he gently pried their lips apart to let the liquid drip into the mouth. The demon obediently lapped up the substance, tongue hanging out as they panted softly.
In one swift movement he pressed their lips together and held them in place as he let blood gush into them. Small hands came up to curl into the fabric of his kimono, trying to ground themself as the drug poured into their body. They trembled in his grasp and he grinned against their lips as their pupils dilated and a flush spread across their cheeks. He adjusted his grip, one hand pressing against the back of their head as his tongue delved into their mouth and the other drifted between their legs.
His thumb pressed against the inside of their thigh and he let out a pleased noise as he felt the slick covering the soft skin. Slowly sliding the digits upwards, he pulled away from them in surprise as his fingers came in contact with the heated flesh of their core. The weakly slumped over, head pressed against his chest and blood dribbling from the corner of their mouth.
"No underwear?" Muzan questioned and cocked his eyebrow as he looked down at them, their form still trembling as they held onto him for support.
The small demon's shoulder shook with silent laughter and he hissed in frustration. He grasped their short locks and yanked them from his chest, suddenly realizing just how much they had been pressing their face against his breasts. A quirky grin was on their bloodstained lips and he growled at the mischievous glow in their eyes despite their flushed state.
"You are." The demon lord's fingers found themselves plunging deep into their core and they threw their head back with a low groan. "The most annoying." He latched his mouth onto the juncture of their shoulder and neck, fangs sinking in until blood spurted out and the other came with a sharp cry. "Demon to have ever served me."
Nobu collapsed onto the futon twitching, eyes unfocused as they stared up at his glowering form. He ripped out his hairpin and let his hair fall, casting a shadow over his face that made his red eyes gleam brighter from behind the curtain of dark locks. The woman sauntered over to the drawer and glanced over her shoulder at their shaking form. Pulling one of the doors open, a dark smile fell on his painted features as she hummed quietly, "I was going to let you pick since you got me in such a good mood, but…"
The demon lord pulled out a crystalline dildo, the length and girth making the small demon on the floor shudder. The toy wasn't new, something he'd crafted awhile back but never gotten around to using. He inspected it as he made his way back; the surface was covered in rock-like ridges, nothing sharp but by the gods would they feel it.
"Its based on Douma's Blood Demon Technique, I saw him use it to kill a woman who was trying to run away." He crouched down so that they were eye to eye, holding up the lengthy toy, "It went right through her up to her throat. It was an amusing performance."
They only grinned wider and he scoffed, of course they were looking for punishment. Why else would they pull such a stunt?
"If you weren't such a fun toy I'd have you beheaded by now." The woman sighed and rolled his eyes before shedding his kimono. They followed suit, hands tugging at their obi before a foot slammed down in front of them, a signal to stop.
"I want it on."
He pulled the strap on and secured it on his hips, eyes never leaving theirs as they stared up at him in anticipation. He gestured at them and they rolled onto their back obediently. A pleasant surprise considering their earlier actions.
Hovering over them, he kept his hands on the insides of their thighs, forcing their legs open as he looked down. Sliding forward, he poked at their entrance teasingly and watched with amusement as they let out a breathy gasp.
“I wonder,” He continued to trace circles over their core with his tip, “If I were to change appearances, would you still be so compliant?”
Nobu let out a low growl and with a burst of strength, clamped their legs around his hips and tipping him onto his back. They looked down at him as his cocky grin twisted into a snarl. Ignoring his glaring eyes, the young demon slowly lowered themself onto the dildo, breath hitching as it forced their walls apart.
“It's different from the others, isn’t it?” Muzan laughed and grabbed their shoulders to roll them over underneath them. They opened their mouth to reply before he sharply thrust forward, the words dying in their throat. He held their legs open and began to pound into their heated core, the other gasping loudly with each thrust and body convulsing with pleasure.
“You got too cocky,” He grunted, shifting his hips so he could get in deeper, “It's not even all the way in yet.”
They mewled out softly as he kept up his relenting pace, “Sh-shut up. My l-lord-!”
He let out a sigh as their hips finally connected, Nobu throwing their head back with a silent scream. The demon lord grinned and placed a clawed hand on their abdomen, pushing down lightly. They let out a strangled cry as he added more pressure, smiling wider when he finally felt the toy buried deep in them.
“A perfect fit, if it had been any bigger it surely would have ripped your insides apart.” The woman hummed, “But I’m sure you wouldn’t mind that, would you?”
He bent their legs forward, their knees folding to rest on either side of their head, and he pressed a chaste kiss onto their nose before pulling out and slamming back in with newfound ferocity. They moaned out loudly as he kept up the vicious pace, hands clawing at the fabric under in an attempt to ground themself. He spread them out wider, a hand coming to play with their swollen nub, and he moaned as slick gushed out around the crystal toy.
Muzan couldn’t feel their insides himself, a fact that made him thrust aggressively in frustration, but watching his snappy pet lose themself in a rush of pleasure was something he found more enjoyable than mindless sex. Their tongue lolled out of their mouth, drool leaking out of their open mouth as they let out moans and cries whenever he’d slam into the entrance of their cervix. He pressed himself against their body, hips pistoning into theirs faster with the new angle, and sunk his fangs into their neck. They twitched in surprise at the pain filling their senses, but he kept his hold on their body, teeth sinking further and further into the soft flesh until blood was staining their shoulders and dripping onto the floor.
Pulling back, he gave a satisfied nod at his handiwork before diving back down to press more bite marks into their bloodstained neck. They gurgled lowly as each thrust caused the wound to spurt out bits of blood, their cheek painted red as he kept up his brutal pounding.
The young demon was close. He could sense it, from the slick pouring out of their sensitive core and their hips weakly moving to try and match his pace.
Until the familiar note of a biwa rang through the air and his head snapped up, teeth gritted in anger.
“What?” He snarled, his movements stopping despite still having the other pressed flush against his hips. He was back in the bloodstained room from before, the putrid scent of the weak Lower Moons invading his heightened senses.
“I’m sorry Master,” Daki’s eyes were wide as she stared at the lewd scene. He glared at the siblings gawking in shock, “We didn’t realize you were busy.”
“Don’t interrupt me again,” The woman hissed before the biwa played again and he was back in his room. He glared at the wall, “Especially you Nakime.”
A soft mewl caught his attention and he looked down to see Nobu rolling their hips lightly, trying to please themself without him. Annoyed, he pulled out and rested the sopping dildo on their heated core, teasingly rubbing it against them.
“Stop it.” They whined and he frowned. Everything was grating his nerves today and he was not pleased.
Muzan flipped them over, forcing the other to hold themselves up with their arms. In one swift motion he seated himself inside them again, his hips pressed against their bottom. They glanced back at him and let out a whine. He barked at them to silence themself before grasping their hips and pistoning into them. They choked out a gasp, the force making their body shake with each thrust.
He was so annoyed.
They came with high pitched cry, arms giving out and upper half falling to weakly twitch as he continued his assault on their body. He ignored the other’s soft mewls as he continued to pound into them.
Everyone was so useless and weak.
Muzan held their limp body up by the arms, hips drilling into them from behind. Tears and drool soaked their face and they were babbling incoherently as he kept up the pace.
By the gods, shut up.
He’d turned them over to shove his obi into their mouth, tying the makeshift gag so tightly their nostrils flared as they tried to breathe. Nobu’s leg was draped over his shoulder, providing a deeper angle at which he could drive the toy into them. Their eyes rolled back and they let out a muffled shout as he hit that certain part within them, the woman grinning before grasping onto their hips to target the soft spot directly.
Why couldn’t everyone just listen?
It was when he flipped them over once again that he’d noticed they’d passed out. Their half lidded eyes glassy and unfocused and gag soaked in spit. He ignored them, continuing to drive into their oversensitive core and enjoy how their body jumped and twitched at his actions even when unconscious.
They all had such painfully, simple tasks. Just follow them. Those weak pieces of shit.
Nobu groggily looked up from their position on the floor, their dazed eyes taking in the man standing in front of them. His beautiful form had been shed, the familiar figure looming above them making them groan. They weakly pulled out the soaked fabric in their mouth and murmured, “Come on, you couldn’t have been hot for a little longer?”
Muzan gave a bemused grin as their docile gaze hardened, his hands already drifting down to his belt, “You’re only nice when I have a pair of breasts for you to gawk at.”
“Your butt is cute too.” They replied dryly.
He tugged at the band of his underwear to let his hardening dick out, the other grimacing as they realized what he wanted,
“Gross, did you fuck me into oblivion earlier so I wouldn’t be able to top you tonight?”
The demon lord scoffed, despite them seeing right through his plan.
“Of course not. Now I’m going to fuck you again, those incessant Lower Moons are still on my nerves.”