See I'm sure with all of us we can work together?
I mean me personally I'd like to see new worlds. Not the repeated ones.
Like Atlantis, toy story, or anything new.
Then final fantasy characters that haven't been used yet.
Like Lightning, snow, zidane, Dagger, and so on...
Maybe a different group that ties back into the heartless again... Like revive enemies or finding of new ones that banded together for another go at taking over Kingdom Hearts and the new princesses.
Or...
A world of the souls that are from the nobodies shells. Then a new enemy tries to annihalate the souls which want to become one with the nobody shells that now do not exist. >.< Grrrrr This is harder than I thought. Original stories that are not having anything to really do with the other stories is quite difficult.
Fill free to ignore me as I rant and throw out nonsense of "ideas".