Actually, the Tales of Series did a spin off like this too. The latest one was Tales of teh World: Radient Mythology. Like .hack,you have a custom char, but you can make a party with characters from other tales games like lloyd and raine and luke and tear. I think if kh did this it would have to be a spin off game. you could be like, the second protector of the light realm, or possibly a previous or future one.it could work, but i'm not sure if it'd have much to do with the other games....but then again, remember the legend about how teh keyblade was used before? maybe in thsi game you can do good or bad things (like fable or that star wars game) thus leading to at least 2 endings - one where you're good and one where you're bad