Fox really hated teleporting and world shifts, regardless of cause. In this case, though, she supposed she couldn't complain. This was where the battle was, so this was where everyone who could and would fight needed to be.

She pointedly avoided the Dark Keybearers, knowing full well she could't take any of them. Instead, she turned her attention to Heartless and specifcally to keeping them away from interfering with the battles between Keybearers. Sora and the others had their hands full as it was.