[ From the smile Finnick gets he's absolutely using it right! Admittedly usually Izuku hears "Midoriya" more often, but he's worked overseas and knows that...Americans? Is Finnick American, he can't even tell (post-apocalyptic American sounds about the same, right - ) but he knows they use first names more and is perfectly happy with that. ]

Blackwhip? Yeah, it's part of my Quirk! [ Since he's a smart guy, Izuku infers that Finnick doesn't know what a Quirk is since he didn't ask "is that your Quirk" and goes on to clarify: ] Er, where I'm from most people are born with some kind of ability or power...so, that's one of them.