A Certain Magical Index and My Hero Academia Challenge

The challenge is this: Have Touma Kamijou confront the Hero Killer, Stain. Stain's whole gimmick is that he kills or maims anyone he doesn't consider a true hero, and he has very high standards of what a hero is. He also believes all villains must be immediately killed and doesn't believe anyone can be redeemed. I would like to see how this meeting would go. Would Stain see Touma as a true hero? Touma would obviously call Stain out for his murders and fight him. Stain's Quirk that lets him paralyze people wouldn't work on Touma because of Imagine Breaker, but because of Stain's insane levels of strength, speed, and weapon skill, Touma likely wouldn't be able to beat him on his own unless he fights dirty or unleashes the Invisible Thing and/or the dragons inside him.

Either that, or have Touma or another heavy hitter from the Indexverse confront All For One.