On a snowy night on the plains when he was ten, Katsuki woke up to his mother running out the tent with her sword. Outside he heard the fat lady with the mole screaming. The familiar vibration of the roars of battle spiked his blood with fire.

"Zuku-" Izuku had stayed in his mother's tent that night. He had wanted to be 'grown up' but sleeping in his mother's tent instead of in Katsuki's bed. Not that Katsuki cared either way, except now. "Damn it!"

"Stay here," barked his dad.

"I'm a warrior too!" he barked back, his sword and cloak already in hand.

"No!" A hand caught the back of his pants. "You're a child! I don't care how good you think you are-"

His dad didn't finished. A body crashed through one of the wood poles of their tent, toppling a wall into a swath of furs. The light of fire broke through the tearing flap.

Outside, his tribe's tents had been set aflame. Against the orange light, everyone's features turned black. Running, screaming, swords flashing, flails, clubs-

Katsuki didn't recognize the hulking figure rising from the collapsed corner of their tent. They were hairier and darker than anyone in his tribe. For some reason, the men of their tribe grew thin, short beards or no beards at all, and most were blond.

The man spotted him, bared his teeth in a macabre grin, and raised a morning star the size of Katsuki's head.

Old instincts sparked to life. Katsuki flew beneath his reach, launching his sword into their gut without hesitation.

The surprised cry of pain came over him like the roof of an old home.

"Katsuki!"

He sliced at the back of the man's knees and kicked him down. "I'm fine, old man! Find mom!"

He had someone else to find.

Sure enough, the tent next door to theirs was empty of both Izuku and Auntie Inko.

Katsuki called Izuku every foul name he could think of. If that idiot was out being a hero at fucking ten years old he was going to kill that Deku himself!

Few paid much attention to a brat weaving in and out of fights. It was dark, the fires barely showed enough to distinguish friend and foe. He saw one of the hairy invaders dragging away a woman of the tribe and took a slice at their achilles. The bastard dropped to his knees, allowing his tribeswoman to free her arms enough to beat him over the head. Being able to defend oneself was a point of major pride for their tribe.

"Katsuki!" she cried. "What are you doing here?"

"A little gratitude maybe?" He flicked blood off his sword, speckling the snow. "You seen Zuku?" He really hated this having to roar to be heard above the chaos in his squeaky peewee voice. Ugh, he couldn't wait for puberty.

"Inko's set up a barrier with her magic to protect the children. I was just leading them to it when -hey!"

But Katsuki had already spotted the tell-tale green of Inko's magic above the orange glow of the camp, now that he knew what to look for. Auntie Inko didn't use her magic very often in public, even though none of the tribesmen had anything against magic. Had to do with deeply ingrained survival habits. But when she did, it was usually to make barriers or draw in things from a distance, reminiscence of her old quirk.

He'd just made it through the tents, fire, and crowds enough to see the glowing dome of green when the back of his neck tingled and his cloak yanked him back.

"A brat with a sword!" barked his captor, also hairy and huge-what were these, trolls? "You must be the prin-AUCHK!"

He sliced, he kicked, he punched and bit. A rabid, psychotic cat had nothing on Katsuki.

The man's blood speckling his face warmed Katsuki's cheeks against the cold, winter air.

But his foe hadn't come alone.

Half a dozen hands grappled with him the moment his captor's grip fell away. One crushed his wrist, forcing him to drop his sword.

And then he heard Izuku scream "LET HIM GO!"

Oh hell no, this wasn't happening. Sure Izuku trained with him under his chief mother's tutelage, but that didn't mean he had the experience or talent Katsuki had.

The low grunt of one of the men and Izuku's pained squawk proved this. One man wrapped him up so tight in his arms Katsuki couldn't breathe let alone turn away. They stepped to the side, giving Katsuki a perfect view of the green ball on the ground which was Izuku. The invaders kicked the curled boy, laughing, while others left to find more entertainment.

Fury, blinding and volcanic, erupted from the pit of Katsuki's soul.

With it came an old, familiar crackling in his palms.

Explosions and fire blossomed into his captor's face. Blood flung up into the air like mist.

And Katsuki was free, flying towards Izuku only to pivot and throw more and more explosions at the men around him, unable to feel the pain of his arms breaking from the recoil.

The troll men fled. The man he'd first exploded ran away with his hands to his face, wailing and eyeless as blood poured from between his fingers.

Sparks kept popping from Katsuki's hands long after they were alone. He couldn't breathe.

"Kacchan! Kachaan!"

Izuku's voice came to him as though from the other end of a long tunnel. A drop of sweat tickled his chin as it dropped to the ground.

The last thing Katsuki saw was Auntie Inko's green barrier closing in around him.