1. Doctor Who
One of those fun things about writing fic for Kingdom Hearts is that with all the world-hopping they do, you can get away with crossing it over with just about anything. And one of the first things I remembered on noticing this was that the exact same thing was true of Doctor Who. There was really only one possible logical conclusion.
This would be the ninth doctor, just to clarify. No real spoilers.
The first thing the kid latched on to was all the traveling they'd just implicitly admitted to.
"You mean, you've been to other worlds too? Have you ever met anyone called Riku? Or King Mickey?"
"King Mickey?" Said Rose, who'd been staring at Donald and Goofy for the last ten minutes solid. "You're not seriously talking about Mickey Mouse?"
"Gawsh, you mean you have met the king?" Said Goofy.
"I think I'm just going back to the Tardis for a while." Rose said faintly, and fled.
"What was that about?" Donald complained. "Has she met the king or not?"
"She… knows him by reputation." The Doctor clarified. "So, tell me more about these 'Nobodies' you were talking about."
Five minutes of explanation later, the Doctor declared "Fantastic!" with the biggest grin Sora had seen all day.