( he lets him drink first and maybe take a moment to breathe and just chill for a minute as he continues checking him for any signs of a serious injury, like an open wound or something, but he seems all right, so vash moves on to the other bit that concerns him. the mention of a brother. )

Well, Koriel. It's nice to meet you. ( he smiles and gives his new companion here the peace sign with his fingers. he's definitely wondering who this guy had been with before arriving here. people who never bothered to name him? what's that about? still, he figures, he shouldn't be prying too much at the moment. besides... there's something else that takes priority here. )

How old's your brother? Describe him to me. I can go look for him downstairs. ( maybe the kid's stuck in the train still. he can just do a quick check. it wouldn't take him too long. ) You can just stay here, okay? I'll come back for you, real quick. Promise.