okay sugar, i'll try my best to help.
make sure you "scan" ability is equipped.
always attack the stealth sneak with physical attacks and combos, until it becomes visible. when it does, avoid its attacks by dodge rolling (fabulous little thing..) try also using thunder on it from a distance if you dont want to be too close. when clayton gets off of the stealth sneak, get behind it and attack it repeatedly. you'll recover MP and then just use fire attacks to keep it away. same with clayton. just use fire against him when youre not beating the crap outta him.
just keep at it darlin, you learn the 'cure' ability for winning the battle which is your greatest gift ever. remember, keep sora equipped with potions and all that fabulous stuff. worry about you, not donald and goofy. they'll recover in two minutes, while you on the other hand...wont. >_<
lol and i cant believe i remembered all that.