When he meets Ben, sometime after Ben is born, Luke realizes that there is something drastically wrong. It’s something that he shouldn’t even be noticing at a time like this, a joyous time at that, when Leia’s holding her baby and Han just seems so overjoyed to have such a miracle in his life...
But the baby’s Force presence is shot through with dark veins, veins of the Dark Side. This isn’t normal, is it? Luke doesn’t know much about what a baby’s Force presence is supposed to look or feel like, but this can’t be normal, can it?
“Luke?” Leia’s voice, jolting him out of his thoughts. “Are you okay?”
Luke nods. He reaches out, carefully, touches the baby’s forehead. Ben is asleep, and Luke is too aware of how fragile he seems in Leia’s arms.
He swears that he can hear the Dark Side whispering at his ear. Go on. It’s so tempting, isn’t it?
“Luke?” Leia again.
Luke manages to just swim up out of his haze. Thank the Force he didn’t actually hurt Ben; it would have been frighteningly easy. And yet this baby feels wrong...
In the midst of that, he starts having nightmares of a burning temple, flames in the sky, and pouring rain with strange armored figures standing in it. Luke always wakes from those nightmares wondering what’s happening to him, if there’s something wrong.
He can’t talk to Han or Leia about it. Combined with that thought he had about hurting their own son, they would most likely think of him as a monster, and they would be right.
So he journals. He writes down his dreams and his thoughts, writes down everything that comes to mind.
“I wanna be a pilot when I grow up!”
Ben looks up at him, and Luke feels a sort of tenderness towards the small boy that’s usually outweighed by fear.
“Do you?” Luke says.
“Yeah! Like Daddy.” Ben grins a toothy grin. “He’s my hero.”
And Luke feels a slight tug of affection towards the five year old. Han adores Ben, and Ben adores his father — practically thinks of him like a god. He wonders absently if in a different life, he could have had that relationship with his own father. Sometimes it’s easy to fear this little boy. And sometimes, it’s easy to care about him, when he’s got that sort of confidence he can take on the galaxy that his father had before him.
When Leia asks if he can help Ben, he accepts. It’s a favor to his sister, and to Ben. To help them both. He just hopes that he can succeed.
Ben grows up, and Luke realizes that he looks quite different from both his parents — black-haired where Han and Leia had brown hair (probably a recessive trait from Han’s mother), and bigger and more muscular than Han ever was. He has a face like an angel from Iego, which reminds Luke only of why he doesn’t believe in angels.
This angel’s face hides a monster beneath.
It’s very subtle, but it’s there. Luke can feel the barely contained emotions that burn beneath the surface — anger, for example, towards his mother that he tries to not acknowledge, and a sort of desire for Poe. They burn like a forest fire, and Luke can’t help but be afraid. His nephew walks on a tightrope between the Light and the Dark and if he’s not careful, he’ll fall.
He can feel the Dark inside his nephew. The nightmares. The moments of anger. Of frustration. Just to name a few. He can feel it, and it scares Luke.
He shouldn’t. After all, Vader was redeemed, and he committed actual crimes. Ben’s done nothing...and yet Luke is afraid.
Children are innocent. Children are blank slates. And yet, Luke remembers the dark veins that shot through his nephew’s Force presence.
The same that shoot through now, only they seem like open cracks. Wider cracks. Darkness is pouring through like blood from a wound, and Luke is afraid...
Fear leads to anger...no, that can’t be right. Sometimes fear is just fear in and of itself. So the Jedi aren’t perfect. So he’s not perfect. He’s tried to all but cut the evil out of Ben, and he’s failing.
It’s after a particularly vivid nightmare that he goes to Ben’s hut, feeling a particularly strong Dark Side presence there. Ben is asleep, and he looks peaceful, almost carved from marble.
Luke knows better. Face of an angel, mind of a monster.
What are you waiting for? Kill him.
The Dark Side presence that all but possesses his nephew taunts him. He belongs to me now. You can’t save him.
Kill him. Stop him before he can take any lives.
Luke ignites his lightsaber —
— and finds he can’t follow through on the deed.
Ben stirs, though, and he knows what Luke was thinking of doing. Luke meets his eyes as they cross blades. He hasn’t thought that Ben’s eyes could get so wide and frightened, and yet here he is.
Before Luke knows it, the hut’s crumbling down on them both, and all goes black.
His temple’s on fire. Everything’s burning.
This is what he’s wrought. In an attempt to prevent a terrible future, he’s only created more of a tragedy.
He’s created a monster. Good as created a monster. All because he was afraid. In his mind, he can hear Master Yoda’s words, almost mocking him.
Anger, fear, aggression — the Dark Side are they.
Luke drops to his knees, tears in his eyes, and they won’t stop falling.