[Never met Kairi? But clearly knows who she is, at the very least, or he wouldn't be asking. The whole act, whatever this is, is so full of so many levels of wrong that he's not sure how to judge what's deception and what's just plain trauma. He might be able to sort it out at home, where he knows what to expect, but although he's not sure he believes in the whole alternate universe hypothesis some of these people have, at least he's heard of it - enough to accept that somewhere, somehow, this probably does make some sense.

No real good option right now but to continue to answer questions and hope he'll say more that clarifies things.]

I don't know specifics. I know Riku spent a lot of time and energy trying to find them. Both were here one day and gone the next, and Robin, the lighthouse keeper, included them in her weekly obituaries, meaning some of the spirits managed to verify that they had died and reported it to her.