I elect for New Orleans from Princess and the Frog to be in Kingdom Hearts 3. I also elect that New Orleans is Demyx's homeworld.

So here's the crack theory, in the form of fic.

Fandom: Kingdom Hearts
Characters: Demyx, Dr. Facilier
Rating: G
Summary: A down-on-his-luck nobody from New Orleans strikes a deal with the devil.

( Can't Play Jazz With No Soul )