Welcome, OneArmedSora!! ^_^
What costume KH costume will you be wearing to AX? Have you found the AX KH thread yet? That might give you an idea of what other people are doing. Lesse if I can find it...
Though it'll be my fourth con (first and second were AX, third was Ani-Magic), this will be my first time cosplaying. ^^;;
I figured that now that I'm more comfortable at cons, I won't feel as uncomfortable to cosplay. Regarding KH, I'll be cosplaying Antisora. I wanted to do Sora, but I figured that most people would probably do the regular Sora, so I still get to wear his clothes and stuff, only the colors are black and gray ^_^.
I think it would scary for me if they were to have a "Cosplay war" between FF and KH, or even within KH itself, because I'd be cosplaying a Heartless, I think, or some type of the enemy, and those are the ones that get attacked, ne? ^^;;;; (I'd better make a good keyblade...-_-)