One day during training, Izuku and Katsuki were teamed up to patrol the city for villains. The whole time Katsuki was bitter about it, and Izuku was just trying to get him to focus on the task at hand instead of cursing him out.

Too focused on themselves, the two nearly ran straight into a villain. And it wasn’t just a teacher representing one. No, it was an actual villain.

The two had tried to call in backup, but the villain had hit them both with his quirk. A hot searing pain ran up and down both their bodies, making them both fall to the floor with pained gasps and grunts. This gave the villain enough time to make a break for it. It didn’t take long for the duo to recover, but they sure as hell felt different.

Izuku weakly pushed himself up from the floor, gritting his teeth as he hugged one arm against his aching chest. He could see Katsuki struggling to get up a couple yards away in the alleyway. “What..the fuck just happened?” The greenette grunted out, leaning against the wall with a forearm.

Katsuki didn’t answer, he was just trying to get up, too. Once he did, he glanced over Izuku. “Are you okay? Why are you holding your arm like tha—“

“Back off, loser.” Izuku smacked Katsuki’s hand away as he hurried over.

The two paused, realizing what exactly the villain’s quirk was.

They’d switched personalities, but not consciouses. Had anything else that changed?

A light thump sounded as you jumped down from the building above, panting softly under your breath. You looked over at the two, “I know I’m late but—Jesus Christ, what happened to you two?” You announced, surprised with how bruised and beat up they looked. “You guys were only left alone for 10 minutes.”

“Maybe if you would’ve gotten here faster, we would’ve been fine.” Izuku spat in annoyance.

You paused, glancing between Katsuki, then Izuku, then back. Giving the spiky blonde a questioning stare. He just shook his head in a sort of I don’t know way.