Two weeks had passed since Katzo discovered his germ-eating Quirk. Nothing exciting happened — just preschool, playtime, and the slow crawl toward Katsuki's birthday.
But two days before the big day, everything changed.
They were in the Bakugo backyard: Katsuki, Izuku, and Katzo. Masaru sat on the porch, reading a newspaper and half-watching them.
"Bet you can't snap," Katsuki said, snapping his own fingers easily. Click.
Izuku tried. His fingers slid against each other without sound. "How do you do it?"
"Like this." Katsuki demonstrated again. Click. "You gotta put pressure right here."
Katzo watched, amused. He already knew how to snap — from his past life — but he played dumb, pretending to struggle.
Katsuki puffed out his chest. "Watch a pro."
He raised his hand to snap again, bigger this time. He pressed his fingers together, face scrunched in concentration.
CRACKLE.
A tiny spark. Then a pop. Then —
BOOM.
A small explosion burst from Katsuki's palm, no bigger than a firecracker. He yelped and stumbled back, shaking his hand.
"Ow! What the —"
Smoke curled from his fingers. His eyes were wide, then gleaming.
"I did it," he whispered. Then louder: "I DID IT! I GOT MY QUIRK!"
Masaru lowered his newspaper, eyebrows raised. "Katsuki, are you alright?"
"I'M ALRIGHT! I'M AMAZING! DID YOU SEE THAT?!"
Izuku's jaw hung open. "Kacchan, that was so cool! You made an explosion!"
Katzo crossed his arms, a lazy grin spreading across his face. "Took you long enough. I thought you said you were gonna be the best hero ever. My Quirk showed up first, you know."
Katsuki's eye twitched. "What?! When?!"
"Weeks ago. I just didn't feel like showing off." Katzo sniffed his own armpit dramatically. "See? No smell. My Quirk keeps me fresh."
"THAT'S THE DUMBEST QUIRK I'VE EVER HEARD."
"At least mine doesn't hurt when I use it."
Katsuki lunged at him. Katzo dodged, laughing. Masaru sighed from the porch.
"Boys. No fighting."
"He started it!" Katsuki shouted.
"I just stated facts," Katzo said, still grinning.
But beneath the teasing, his mind was racing. His Quirk is awake now. Next copy window, I can take it. If the mutation doesn't ruin it.
He glanced at the corner of his vision. The HUD was dark. Quiet.
Not yet. But soon.
Izuku tugged Katsuki's sleeve. "Do it again, Kacchan! Can you make a bigger one?"
Katsuki smirked, flexing his smoking fingers. "Obviously. Watch this —"
Pop. A small spark.
"That's it?"
"SHUT UP, KATZO."
Masaru stood up. "Inside, all of you. We're not having a fire in the backyard."
As they walked toward the house, Katsuki kept staring at his palms, grinning like a maniac. Izuku asked a thousand questions. Katzo hung back, quiet for once.
Two days until Bakugo's birthday, he thought. And about two weeks until my next copy window.
He smiled to himself.
Perfect timing.
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Author here:
Any quirk mutation ideas for bakugos quirk?