[Xehanort hesitates, eyeing the boundary. Urashima's trepidation doesn't really affect his decisions any, after all if it held up to THAT, a measly fireball wasn't going to do anything either.]

The only magic I know with any significant power is probably not a good idea to use here. And if that barrier could hold up against what I did a moment ago, what is a little fireball going to do?

[That's a 'no', likely.

Probably.]