So what's stain like in your rewrite? In what ways does he differ from canon?
Ah, Chizome "Stain" Akaguro the ex-vigilante serial killer who is obsessed with All Might.
Within my rewrite: Chizome started out as this anti-hero* vigilante known as Stendhal. He was smart, quick on his feet, and, of course, knows knows how to handle the blade. He started out as someone who just wanted to pick up the slack of Heroes and with a noble goal.
However, very quickly his mindset changed and how low he's willing to go went deeper. He soon started killing those he previously just tied up and left for the Heroes and police to deal. He was willing to work with villains such as the likes as Kuin Hachisuka. He began to justify his actions as "Heroic" and denied any & all criticism that went his way.
After his fight with Knuckduster, he shed the Stendhal title and adopted the moniker Hero Killer: Stain. He also cut off his own nose.
And he began comparing all Heroes to All Might. In his mind: if a Hero couldn't live to the heroism of All Might, to his version of All Might, then they're good as dead. So, he started killing Heroes. He killed Heroes who were actually corrupt, those he randomly ran across on the street, and most importantly those who tried to stop him/get in his way.
His criticism of Hero society is grounded in reality but the way he goes about it leaves his message muddied and not as efficient as it could be, and innocent people are often hurt by his actions.
Also, Chizome is one of All For One's targets. Wanted by the Demon Lord for his quirk. (Not that he ever told Tomura Shigaraki this. Though, he did chew her out for letting him slip from her fingers as soon as Chizome's arrest became public). All For One wouldn't go after him himself, instead he would send pawns after Stain. Which the pawns just ended up dead. Also, Chizome became a target after he became Stain.
So, my version of Chizome is similar to his canon counterpart, there isn't any major differences other than him being wanted by AFO for a couple of years. But I do hope you liked what I got about my version of rewrite!Chizome Akaguro so far.
*The character type (doing bad things for good reasons) not anti Hero.