It's Not a Muskateers Reference!

I Didn't Mean To!!

14 days till sports festival

Izuku was drenched in sweat as he punched at a punching bag, pushing himself to his limits. He needed to work harder than everyone else if he wanted to be a hero, after all.

Eventually, he stopped to take a water break, and sat down on a workout bench. Izuku gulpped his water down greedily, leaving only half of the water in his bottle. He wiped his chin, as some of the water had spilled.

Izuku looked up as he heard someone approaching him. He was met by a shirtless Kirishima, with a towel drapped around his shoulders. "Hey, Midoribro!!" Kirishima grinned, and Izuku smiled back, "hey Kirishima!!"

"Wanna do a quick spar?" Kirishima asked. Izuku nodded, "yeah, sure!"

Izuku stood up from the bench, and both of them went over to an open area in the gym.

Izuku and Kirishima shifted into fighting stances, and Kirishima hardened his skin. Since Izuku didn't have good control over his quirk yet, he didn't want to activate it unless necessary.

They both charged at each other, Kirishima throwing a punch. Izuku rolled under, popping up behind Kirishima. Izuku then threw a hook at Kirishima, who was turning his head, causing Izuku's fist to collide with his cheek.

Kirishima's quirk stopped working, but neither of them noticed, as Kirishima recovered and threw a punch at Izuku's side. His fist hit rock hard skin.

"What...?" Kirishima said, confused. Izuku looked just as confused, "uhm... why d-do I have your quirk...?". The hardening quirk turned off.

"I don't know, bro... we should go tell Aizawa." Kirishima said. Izuku nodded, and they both went to go look for their teacher.

When they saw him, they both ran up to him, yelling "Mr. Aizawa! Mr. Aizawa!"

Aizawa groaned, pinching the bridge of his nose. "What is it, problem children? Did Midoriya break his arm again.."

The boys both shook their heads, Izuku looking mildly guilty for constantly breaking himself. "No, not this time... I um..." Izuku trailed off, not knowing how to say how it happened. Kirishima finished for him, "my quirk stopped working, and then Midoribro started using my quirk instead!! We don't know how it happened?"

Aizawa quirked an eyebrow, "can you show me?"

Izuku nodded, and hardened the skin on his hand. His face looked just as scared as Kirishima's. "D-do you know wh-what's going on?" he asked, turning the quirk off after.

Aizawa shook his head, sighing. "Could this be some sort of effect of your quirk, Midoriya?"

"I don't th-think so... i-it's just an enhancement quirk, s-so I don't s-see why it would do th-this.."

+++++

Eventually, they went to see if anyone else in the UA staff might have an idea of what happened.

All Might spoke up unexpectedly, "I think I know what's going on."

Midoriya and Kirishima both looked equally hopeful. "Y-you do?!" "Can it be fixed?!"

All Might nodded, "if this is what I think it is, then yes. There is a villain called All For One, with a quirk named the same thing. He can steal others quirks, and either give them away, or choose to keep them. If what I'm thinking is correct, young Midoriya might've developed the quirk All For One."

Kirishima seemed plain confused. "But.. Midoribro already has a strength quirk?"

"Well, it is possible to have multiple quirks, take Todoroki for example. He has ice, and fire." Midoriya said, mumbling slightly.

"Young Midoriya, did you take his quirk after touching young Kirishima?" All Might asked, his signnature smile on his face despite the situation. Midoriya nodded, "I-I think so, yeah."

"Alright, can you try to give it back to him?"

Midoriya nodded, and turned to Kirishima. He hesitantly put a hand on Kirishima's shoulder, and closed his eyes, focusing on trying to transfer the quirk back to Kirishima.

He opened one eye, looking at Kirishima, "d-did it work..?"

Kirishima hardened his skin, and nodded, "its back! That's such a cool quirk, bro!"

All Might's smile faltered slightly, "I'm afraid not, young Kirishima.. that's a power filled with coruption. It makes the user crave more and more power, until they end up a villain."

Midoriya looked at him, a mix of shock and horror on his face. "H-how do we know i-it's actually A-All For O-One..? C-couldn't it be a d-different quirk..?"

"Well, we can't be sure... it would be best to test you for any sort of evidence it's not All For One" All Might stated, not entirely wanting to believe it either. This was his successor, after all.

+++++

They ended up having Midoriya take a DNA test. One of his reletives might've had this quirk.

He was sitting alone in a hospital room, waiting for the results. As he was waiting, he had noticed strange markings appearing on his fingers. The tips of his fingers were a dark purple color, similar to the color of Kurogiri's mist. The purple seemed to slowly wrap around his fingers, fading away near the base of his fingers. It was darkest at the very tips.

He stared at his hands, trying to figure out what the markings were. Probably an effect of this new quirk..

Midoriya heard the door open, and looked up, seeing All Might with a disappointed look on his face. He started off by saying, "young Midoriya, do you know anything of your father?"

Midoriya contemplated this for a moment, before he shook his head, "not really.. Mom says he works overseas, and has a fire breathing quirk, but he left when I was two. I don't remember him at all."

All Might sighed, "young Midoriya, your father... is All For One."

Midoriya looked at him in shock, "so you mean..."

"You're the son of the most wanted villain out there, and your quirk is All For One."

A/N

d'you like the title? I thought it was funny.