Huh. His short answers actually do make them think of Batman.

They take a step forward just to make sure they can without falling, then flop down to sit beside him. "Training myself," they decide. "And fun. Never got to do it before showing up here. Don't know why I didn't try before."

'Training' makes them remember something--just in case, and this person seems new, so. "Should probably stay away from some...kids who look like me, but have green shirts. And there's a guy with a baseball bat, he's a jerk too." They do trust the second Chara they've met quite a bit, but still. Mixing them up with Underground monsters seems like a bad idea.