An FF World in Kingdom Hearts...
I know, it's not going to happen. But I was just wondering what would happen if it did.
Would we see Midgard, with its Mako reactors extracting Hearts from the Lifestream to use for energy, leaving behind only crystaline remnants and ever growing numbers of Heartless?
Or perhaps the world of FF6, with Kefka ruling over an army of Magiteck Armored Heartless (randomly killing them when it suited his whims)?
Maybe Spira? Jecht loses his heart to darkness, and a world-destroying Sin Heartless roams the land.