[Dude's in luck, because Prompto looks like he has no idea what Sakon's talking about. Tell away, friend!]

I... don't know? I mean, yeah, I've got a name--a different name from my other name, I mean--but I don't know what it does yet. What's yours? Uh, your name or your vessel form. I'm Prompto!

[He introduces himself with a nod, bouncing slightly on his heels.]