[demon of darkness]

it appears that both terra and riku used darkness for good. if their was a villian that used light then he would be similar to xehanort but different also. in kingdom hearts white hair, tan skin, and yellow or orange eyes, are physical traits of someone who uses darkness. so if someone was a villian of light then they would have brown hair, blue eyes, and lighter skin. we can also assume that if darkness can corrupt the heart and create a heartless, then light can also corrupt a heart and create a light version of a heartless. xehanort beileves darkness is supreme, so a villian of light would beleive light is supreme. xehanort wishes to destroy light, so a villian of light would wish to destroy darkness. in other words this is probably the plot for a future kingdom hearts game.