all of kingdom hearts there isnt really a good guy who is black on the game

So how is a black person suppose to sound? Hmm? They have Japanese voicing obvious Caucasian characters in Animes. 

There is no arguing with the complete fact that he isn't black. Facts can't be argued.

Just make a song of the south world and everyone will be happy!

Sadly if they put a black person in the game just to have a black person in the game, the character might just be a stereotype.

I've seen an anime with a transgender black person for comic relief. (as one of the main characters) And since that is one of the few times I actually saw a black person in an anime setting, I don't feel Japan has a good track record of portraying them. Though if they were to make one in KH that wasn't just a stereotype or comic relief, sure why not, but I would rather them not if they can't succeed at that.
After all I don't want KH tainted any further by media for "IT'S RACIST TO BLACKS!"
Though on the bright side, if that happened, they might get censored to having blue or purple skin, and Xaon might like that.

 

To me skin color is like hair color, it just effects how attracted I am to someone.

Sadly the disney side doesn't have a good track record of having black characters (there's only one cartoon movie I can think of in recent years with a black main character from Disney), and I don't think there's many blacks in Square's games either (they could have the Final Fantasy XIII cast though, one of them is black). So in the end they'll have to go original character. I just hope they don't go the stereotypical route...a lot of minorities in older Disney movies aren't portrayed nicely (they're portrayed stereo typically), so it would be bad if KH channeled some of that...