User blog comment:Trident81/The Most Powerful Quirk/@comment-35202892-20180713093405

I'd say they Nerfed that copy kids abilities from class B. If he was able to hold the quirks indefinitly or maybe for a couple hours, or even hold multiple quirks at once, he could have been one OP character who would have made class A easily. However, if we're looking at quirks already present, than i would have too say all for one is pretty powerful, it got a little nerfed due to All For One giving out quirks willy nilly, however if he stopped handing them out and stockpiled them then no one could stand up to him. There are those though who would argue that Overhaul is better, and due to the fact that i dont read the manga, i can;'t be too sure of its full capabilities, but from what i've heard about it the user needs contact with whatever he is "overhauling" at the time right? Assuming this is correct then All For One simply needs to comprise a ranged attack power and use it against Overhaul from a distance. However seeing as how i dont know the fighting style of Overhaul and that All For One was a little obsessed with punching instead of using his quirk to its upper limits range wise, i cant say who would win in a fight definitively