Take a close look to all the enemy card abilities you have available and get accustomed to the cards you have in your deck. Think of what combos and attacks you can pull. Its really hard i know.(even though i beat him the first time i fought him ^.^) Everytime you see the mickey card, get it. Only card break the combos and nothing else. Don't use the refil card on your deck unless you really have too. Keep watch on his cards he has stacked.
You don't really have to do any card combos, well maybe your most powerful one might help... And i hope your talking about the second riku replica battle.
EDIT:
I forgot you can't use mickey in this battle.... this is what the strategy guide (that i do not use, i got it for collecting!) said.
Quote:
The Riku replica usues dark aura a lot and you don't have the zero cards to break the attack every time. Instead, use combos to card break his attacks and try to land as many of teh Dark Mode sleights as possible. A few Dark Break attacks are enough to get his HP down significantly!
The only enemy cards riku has is Riku and Shadow.
End quote.
