It would be lolarious if the fairies had to make their own clothes out of whatever's lying around, but. Hmmm.

You just want to milk porn out of this, don't you. Well, you could go for the KH2!Fairy feel (same outfits, just shrunk and simplified) or the Peter Pan!Fairy route (like Tink, just really simple bits of clothing); it fits, considering the characters who spawned the event? XD Personally, with Vexen I'm going for the latter-- vest, shorts, stupid hat, and boots, all in blue. *_*

As for what happens to their clothes when they transform back: I'll leave that to the discretion of the muns. :3