I'll see what they say on the subject.
I have sadly never done any cosplay.
the closest I have ever come is dressing up in an awesome Batman mask (it looked exactly like Michael Keaton's mask) and freaking black sweat pants (I couldn't help it. it was like 30 degrees outside on Halloween and snowing. it blew). I would just love to be an Organization XIII member. I'm not worried about being a specific member, just the mysterious figure. but alas, I can't sew that well and I can't afford those prices I see for custom costumes.
actually, now that I think about it, I might still have my blue duster vest, and I have a black wig...I could always be Rinoa. just get the rest of her outfit together and sew a couple of little wings on the back of my vest and there she is.
I personally love Xemnas. I have a fictional character crush on him.
and Axel. and Reno (AC). and Cloud (AC).