Definently Sora. Unless Naruto goes four-tails then I don't know where the battle would go after that. I wonder if Sora can use the keyblade to lock the nine-tails away inside Naruto forever...
Replica Riku was always tough for me for some reason. Every other battle was just spent in anticipation for another fight with the Replica which I knew would be really hard.
Yeah it's a little unfair that they only released Final Mix in Japan but in truth I really don't care very much about a few extra keyblades, and some special battles, and some...ok maybe I do care a little!
I don't think it is a bad thing, but I think that opinions on that may be different from person to person. I mostly just go with the flow, not caring about if there are girls in pe with a majority of guys. In my current class the four or five girls just sit around a basically do nothing, so it's like they're not even there anyway.
Speaking of which, why is Mickey's keyblade called "Darkside"?
And more on topic there is Sora, Riku, Mickey, Roxas (does he count?), Terra, Ven, Aqua, the old dude that pwn3d Terra, Ven, and Aqua, the old dude's apprentice, Kairi (she probably doesn't count though), and I feel like I'm forgetting someone...Leon maybe? No he could only hold the Keyblade, not use it.
Bond of Flame and the lionhead one (leonheart or sumtin like that). I even found a company that makes and sells replica keyblades of the, I can't remember it's exact name, the Leonheart (full metal too!) and I only need like $50 to get it too! They don't make the Bond of Flame though and I'm preety bummed about that.:(
Lol, thats pretty funny. My friend has been trying to do that for a while without success and I don't think I am going to tell him, just give him hints and stuff to mess with him XD!
And I'm not going to try it because if my firlfriend found out she'd beat the snot out of me!