Auntie Inko and Izuku apparently were one of the few survivors of some secret witch village or some shit. Apparently this world had magic, not that most of the people here seemed to like it. Witches and wizards hid away in the forest for a reason. Not that it helped them much this time.

Katsuki got to hear the whole story sobbed from Aunt Inko to his parents while he 'played' on the rug with Izuku. Not that there was much playing. After a night of peaceful rest and a full stomach, Izuku was acting like any other baby, gumming his hands, looking around, maybe eyeing Katsuki's hair and flexing whatever hand wasn't preoccupying his mouth.

"Don't you even think about it," Katsuki hissed.

Or, as the adults heard it. "Onu eee inn buuit."

Izuku's dad had apparently stayed behind so that Inko and Izuku could escape, and there was a general assumption in the tent that the wizard was dead.

Katsuki took to watching his parents expressions. They taught him more than what Auntie Inko blubbered.

And turned his back on Izuku. Bad move.

A sharp pain wrenched a yowl from his mouth. Izuku had tight hold of his hair, and seemed insistent on eating it while it was still attached to the scalp.

"Ah! No, Izuku! Let go! Bad!"

Even before Inko had reached Izuku, Katsuki was clawing and punching with every bit of his carefully practiced baby dexterity.

Now Izuku was the wailing one, with four neat red lines across his face, and a few scratches elsewhere. Good riddance.

"Katsuki!"

His mother swept him up. Indignation rose with him. Why the hell was he in trouble now? Did she want him to just let the fart knocker tear off his scalp?

"I'm so sorry," she was saying to Inko.

"It's fine, they're not even one yet-when's his birthday?"

"I didn't even know he could do that…" he heard his father mutter.

For the first time in his new life, Katsuki felt a swelling bubble of pride.

And then he got a closer look at the red welts across Izuku's face and that bubble popped.

Idiot. He'd just messed up a baby. An actual baby. And Izuku at that. And he'd actually felt proud of that for a moment?

The regret didn't last long. It wouldn't be the last time Izuku would made a go for his hair.

At least time passed more quickly now that he had to defend himself on top of training. Izuku was technically a few months younger than him, but when Katsuki started walking, damn if Izuku didn't nearly kill himself trying to walk with him. If Katsuki ate something, Izuku had to too, so Katsuki had fun nibbling peppers and watching that hell go loose. When Katsuki shed the diaper for the true dignity of the toilet (eons before his parents even though he was ready for potty training), Izuku had to try too…and fail, meaning Katsuku got to smell urin and feces following him around until some damn adult would listen to him long enough to take care of it.

It was a long, solid two year reminder of why he'd gotten into bullying Izuku in the first place. It was like being followed by the paparazzi. A stinking, drooling paparazzi.

But…and he breathed in deep every time he reminded himself this…he was the bigger man. He was older. He'd freaking died for this guy. He could put forth the brain power to remember those painful life lessons he'd learned in the previous life and not torture his, uh…friend? Rival? Protagonist?

But this wasn't Izuku. This was a toddler. A stalking toddler-

No, no, he couldn't fall for that temptation…

It was only because of his supposed 16 year head start on maturity that he didn't do worse things to Izuku than let him try his hot pepper snack. At least Izuku grew out of yanking on his hair.

His 'tribe,' as he'd learn to call it, had a reason for living in tents, apparently. Every six months they'd pack up, with all their horses and cows and other shit, and start moving. Katsuki was born in a gray canyon of sorts, then they went to some wide prairies for the winter, then some sort of sad excuse for a forest, then back to that weird craggy gray canyon. It was definitely untamed wilderness unlike anything Katsuki had known back in Japan, which was mostly green and ocean. While there didn't seem to be much life, outside of the deer and buffalo the hunters would bring back, he found he liked the vast open space. It gave him the impression of having an abundance of air and when he finally could get out of his bed on his own, he'd start his morning going outside and breathing it in deep. The grasslands were more often than not dry and gold, the craggy canyon cold, and the bushy, short-tree forest a faded blue-green, but there were no buildings, or other people besides his tribe, for as far as the eye could see. Katsuki could spend hours daydreaming about running as far and as fast as he could for as long as he wanted.

And one day, when he was four, he couldn't resist the temptation any longer.

His morning breath turned into a run.

He sped past the tents, past the roped off corrals for the cows and horses, past the yipping shepherd dogs, then finally burst past the last line of their encampment. It had rained the past week so the prairie had a rare green tint of live grass that came up to his chest. He laughed out loud as his feet flew, raising his hands to the sky, remembering how he use to rocket up by the strength of his quirk. Surely he'd be getting it soon, right? Surely-

A hand caught the back of his tunic, clotheslining his throat on his collar.

"Whoa there. That could be dangerous."
The guard had the gal to smile at him while he choked his throat back into working order.

And the moment he did have breath-

"Fuck you, old man! I'll show you dangerous!"

"Hold on there," the guy was chuckling, and Katsuki might have too if he held up a swarmy little kid making threats. "I'm just keeping you-YOUCH!"

Katsuki hadn't been coy when he said he'd been training.

Flexibility, strengthened core muscles, and sheer rage got the guard's arm in his grasp and his teeth on his wrist.

His Mom was her most flummoxed yet when she had to break up a fight between a full grown man and her tiny spawn.

Yeah…he probably should have been above that. But the guy nearly choked him to death! You don't just grab a kid by their shirt!

He still got a reputation in the tribe for being feral. Damn people don't have eyes.

At least Izuku thought he was cool…

Yeah, that didn't help.

"You bea' up a grown up?"

"Tony hardly counts as a grown up."

"Who's 'ony?"

"Damn it, Zuku, he's been two tents over since you were a baby! The guy married to the fat lady. With the mole?"

"Mom says she no fat, she's 'turdy."

"Say sturdy seven times fast."

"S'urdysurd-d-derd, derdy, durd-"

Katsuki allowed himself a cackle.

Izuki wasn't fazed. "Sturr-oh! Birdie's out! Le's play wi' her!"

"Sure, have fun, bye."

"Kachaaaaaaan!"

"One squirt is enough for me, I don't have the patience for two, you know that."

"You're kid."

"Sure. Bye."

"Nooooo! Wai' for me!"

And then damn Birdie spotted Izuku and him and started after them with all the intensity of a lion on a gazelle. She was technically a year older than them, but you didn't exactly have a wide choice of playmates in a tribe of two-hundred-something.

That extra year meant nothing, though. She was dumb as a bag of turds and smelt like them too. Didn't her damn parents bathe her? Katsuki seriously considered asking his mom to investigate, since technically she was the Chief. Of course she was the Chief.

"Zuku, you shudn't play wit him. He bad."

Katsuki slapped a hand on his forehead and let it down slow. He knew she could talk properly, he KNEW she could. Izuku had an excuse, but girls were suppose to be faster at learning how to talk to begin with.

"Kacchan no bad," said Izuku, as though simply saying it solved everything.

Aaaand, yep. There's the smell. Just had to get his hand past his nose.

"I'm out."

"Kacchan, wai'!"

"Wait!" cried Birdie.

He just wanted to punch both of them and be done with it. He really did.

But he didn't. He just ran away too fast for them to catch and then plugged his ears when Izuku started to cry.

See God? He tries. He really does.