he's a bastard at low level, i just fought him on friend's account.
do everyone else's tips.
also when he does that thing when he attacks from above, and you have to dodge by jumping, try to pack in a lot of jumps, you could probably get 10 jumps each time.
use limits (beasts), and summons, dont drive, you might get anti
you should have the mp haste keyblade right? i would use that
er...equip a buncha healing items
did you level up your forms? i had aerial dodge lvl two and high jump level two so i was able to dodge most of his attacks
if hes really that big of a pain, go to another world and come back at a higher level