[Look he's used to the role of the younger brother, this isn't unusual to him. But he's honestly surprised at how upfront Katsura is being about this and even when he breaks the hug he looks up at him curiously.]

That'd be the only time I'd be disappointed in you, Katsura. You can't give up when we've come this far. [A pause.] We need you. And...you guys found out some stuff in the tower didn't you? It wasn't all for nothing.