It was a normal day when the Big 3 came into your classroom to train you now that (most) of you had gotten your license exam. You went to Gym Gamma and you all had to fight Mirio Togata, 1 V the class

Aizawa: begin.

Mirio activated his quirk and suddenly his quirk came off

Mina: WHA?!

Mirio: oh, sorry!

Mirio puts his pants back on

Mirio: Hmm, I see, most of you specialize in-

Deku rushes forward and tries to kick Mirio but he phases through him and lands on the ground, then Sero and Jirou shoots their tape/earphone jacks at Mirio but they also fly through him hitting and destroying the rock behind Mirio

Mirio: well I'll just have to get rid of the long-range fighters first

He permeates into the ground and appears behind Jirou, but his clothes have fallen off again

Jirou: AHHHHH