No one pov
Infinite, AKA Izuku Mugen fly around the city, until he heard that today was U.A. first day. He fly towards U.A. and he used the Phantom Ruby to hide his presence.

At the training ground are Shota Aizawa AKA Eraserhead, who was doing a Quirk test with his class.

Shota:Now, Katsuki Bakugo, throw this ball with everything you got.

Katsuki nodded and goes to the center of the circle.

Katsuki:You want my power, you got it.

He throw the ball with his explosion.

Katsuki:DIE!

Then Shota show the device.

All:AAAAHHHH! 704 METERS!

Infinite(thought) :No surprise here.

Mina:So good. We can use our Quirks as much as we want. This is fun!

Shota begin to smile.

Shota:So, this is fun, huh? How about we make this more fun. The last place gets expelled.

Ochako:But we just got here. It's not fair.

Shota:Fair? Do you remember what you all did to my nephew, Izuku? You're lucky that we didn't throw you in the Tartarus, along with All Might and Xtreme. Now shut the fuck up and start the test.

... :Jeez, Eraserhead. I knew it you're strict.

A voice was then heard.

Shota(thought) :That voice.

Izumi:Who are you?

... :Oh, right. I'm still hidden.

Then the voice revealed himself. It was The Vigiliante Infinite.

Infinite:So this are the new generation of heroes, pathetic.

Many begin to fear, because they know who stands in front of them. Others didn't know he was.

Mina:Who are you?

Infinite:You may call me... Infinite.

Tenya:You Villain, you're under arrest for villainy acts!

Infinite:So does he had a one brain cell?

Katsuki:LISTEN HERE , FREAK! YOU EITHER LEAVE OR I'M GONNA BEAT THE SHIT OUT OF YOU!

Infinite:My name is... Infinite.

He kicked Katsuki in the wall.

Izumi started to use her telekinesis, but Infinite moves to fast for her and appear in front of her.

Infinite:So, you're the one who beat Izuku?

Izumi and the others widen their eyes when he said Izuku.

Izumi:How do you know Oni-chan?

Infinite:Well, he's not you'r brother. I meet him 2 mouths ago when he was about to be killed by thugs. I managed to save and heal him. Then I looked into his memory and what I saw disgusted me. You, along with you'r shitty friends betray him.

Then Katsumi jumped in front of him. But Infinite teleported away from her.

Katsumi:Tell me where's Ichan!

Infinite:I wouldn't tell you even if I knew it. We part away after I healed him.

Then out of nowhere, he dodge a bullet from Snipe. All teachers of U.A. comes,even All Might and Xtreme.

Infinite :Well, look who's coming. It's the idiot duo. Ass Might and Bitch Xtreme.

AM:STOP RIGHT THERE, VILLAIN!

Infinite:I'm not in the mood for a fight, but if that's what you want, then come on.

He began to taunt him

All Might charge at him, but Infinite easily dodge it. Then with a fist in the jaw, he sent All Might in the wall.

Infinite:Eraserhead, you'r Quirk doesn't work on me.

Shota widen his eyes when he heard that.

Shota:How?

Infinite:Easy, I'm quikless. My power it's not a Quirk. My power is a mystery for all of you.

Katsuki:LISTEN, FREAK! YOU'RE GONNA TELL THE SOURCE OF YOU'R STUPID POWER!

Infinite:The source of my power is none of you'r concern.

All Might got out of the wall.

AM:YOU'RE GONNA TELL US THE SOURCE OF YOU'R POWER! I INSIST!

He charged again, but Infinite said.

Infinite:You'r insistance is futile.

All of them begin to float. Then he knocked out All Might.

Infinite:This is goodbye, for now.

He teleported far away. Then he take of his mask, revealing none other than Izuku Mugen. Then he change his appearance with the Phantom Ruby. His tail become two yellow tails , his ears change, becoming like Tails ears, his red eyes became blue and his white hair becoming yellow.

Izuku:That was something.

He make his Infinite outfit dissappear.

He enter into his apartment and he was greeted by his daughter, Eri.

Eri:Papa.

Izuku:Hey, snowball.