When I was playing the game on Chain of Memories. I could never defeat Vexen, dunno why I must be because I never gave Sora sleights?
Anyway after I did (which took me 3 DAYS!) I accidently dropped the game and broke it.
Vexen is bad luck! REALLY BAD LUCK!!!
Never trust Vexen, that's the moral of the story; skip, his scenes, kill him quick and most of all STAY ON LEVELED GROUND.
Don't say I didn't warn you lol.