Kingdom Hearts II OMG! final mix is hard

i try once then battle marluxia, it was hard because you omly have 90% of hp and u have to prevent geting hit. i also battle zexion,vexen,and lexaeus. that was hard to. reason: zexion use spell sota when i try to hit him then he get my life to 1%. vexen is kina easy but he sommen antisora so i have to defeat him frist then attack vexen and then by that i lose by a antisora. lexaeus, too hard because he can get your life into 1% then your you defeaded. the easy one is roxas (dont ask me) if you want a anser to me. tell how to deafeaded them:rockdover: