Izuku would have been prepared to believe that inspiring someone as if by magic could be a Quirk. He's also learning that there are people from other worlds that have multiple powers or even bona fide magic.

Fabian's saving grace is that he can still dance well even while he's bragging. Izuku resists the urge to sigh and roll his eyes. Instead, he takes a moment to stare into the middle distance before finding his feet again.

"You're fun to dance with, at any rate. What do you do when you miss a step? I'm having trouble..."