Keith really, really doesn't like fighting.
Maybe it started when he was a child, when playground tussles evolved and changed into getting held against the brick wall of the school as whatever play-yard bully of the year pummeled Keith like it was easy. Keith didn't like fighting, violence, the screaming pain that follows when Cai or Emil or whatever asshole it was landed another solid punch to Keith's tiny, puny, lanky body.
He was quiet. Maybe that's what lead the others to isolate him, what lead the bullies to call him out constantly. He was quiet, and he was odd, and he didn't have a mother like everyone else did. She left and left Keith with one single memory of her: the swish of a cape, a sweet kiss pressed to his forehead, the moonlight shining through the window to remind him of his loneliness.
And God, if his life were like a TV show, that moonlight would have been a common theme, a recurring pivotal plot point to come back every time someone else left.
His father. Moonlight.
Shiro, his brother. Moonlight.
The night he got kicked out of the Garrison. Moonlight.
Every single fucking night in that shack in the desert. Moonlight.
Keith had learned to hate the moonlight, to look at it and feel scorn. To, in a way, blame it for everyone leaving him. It wasn't the moon's fault, was it? How could a hunk of rock cause all of his life's problems?
But it was there. It was easy to blame.
Either way, Keith vastly preferred the sunlight. Sunlight meant that there's nothing hiding in the corners of an empty home, sunlight meant people coming outside, sunlight meant new days, new opportunities, a chance to try again.
Sunlight meant crystalline water, shimmering and sparkling and shifting happily under the careful watch of the sun. Sunlight meant warmth on the skin, akin to a hand resting on his shoulder, akin to someone leaning into his side comfortably. Sunlight meant laughter, loud and familiar, dancing down the hallways of the castleship, reaching Keith and going straight to his heart.
He asks Lance about it one day. They're lounging around in the common room, a sacred moment between battle and preparations, not really talking but being. It comes out of nowhere.
"What do you prefer," he had begun, watching as Lance's eyes flick over to look Keith full in the face, "sunlight or moonlight?"
"Moonlight," and it had been said without a second thought. Flippantly. "Y'know, 'cause like...yeah, sunlight is nice, but there's something about being alone with just the moon and the stars that's amazing."
What? Keith was sure, almost one hundred percent positive that Lance was going to answer with sunlight. How could the human personification of it say otherwise?
"Why, what do you prefer, lone wolf of the night?"
"Don't."
"Okay, sorry, yeesh. Just curious." There Lance goes, regressing, feeling like he's said something stupid again. Save the situation, something in him demands, bring it back.
"Sunlight." Lance is half-way through a confused noise when Keith repeats it: "I prefer sunlight." Then he feels like he's said too much, so he stands, stretches, exits before Lance can ask another question.
It's this encounter he finds himself thinking of as he pulls the handles of the tiny Galra jet fighter together. It's Lance's smile he finds himself thinking of as he speeds towards his impending doom, moonlight coming in rays through his dashboard. It's the casual way Lance calls his name, grin brighter than the sun itself stretched across his features that Keith thinks about as he squeezes his eyes shut and sends off a final prayer to whatever God may be listening.
Well. Keith doesn't like fighting. But he does like saving people.