Well, [Vaan said - even the voice had changed. He was a near-perfect replica,] you couldn't tell, right? Nobody seems to be able to tell. Perhaps those kidnappers could - but, uh...
[And then, around Lightning, another illusion - whoops, it almost looks like they're on cracked land, floating in the sky. The wind feels like it's blowing around them, even though it's not. He only keeps it up for a few moments, though. He hasn't trained too much.]
Sure, they can't hurt people. But the mind's a powerful thing - plus, there's quite a few people those kidnappers trust, right?