Who the hell is that blond person?
Not known (but he is NOT Tidus!). If you're talking about the Blonde haired Kid whos been sighted in KH2 and at the end of COM he been called Sora protaganist. The guy in your avatar is probably Riku though. There were two black caped men in ASAS. Look at the screenshots for Deep dive if you want to know more about it. http://www.kingdomhearts2.net/gallery/