[Prompto is in luck! Even if he gets Gandalf's name wrong in the future, the old wizard probably won't mind too much. He is, after all, a wizard whose various names among various people tend to (loosely) translate to things like 'that dude in grey' and 'staff guy.']

Gandalf is my name, and Gandalf means me. And you may thank me by giving me your name in return and by joining me for a cup of something warm.

[Coffee, tea, cocoa - even warm milk will do, if any exists that doesn't taste like ashes here. The point is, Gandalf rather thinks the boy could use something, and one should never underestimate the soothing power of a good comforting drink. That much quite literal blackness in someone's young life is concerning.]