Originally Posted by
Charismatic
I spent a LOT of time refighting Final Xemnas in the original release of KH2 (I really like the music in the last form, sue me!) so he wasn't a big deal to me, minor adjustments needed to be made that's it.
I usually just quick run around when he's spamming begone begone begone. (Usually staying semi-close so I can dash up and hit after the last one)
I also generally tend to pop riku's limit when he does that crap where he tosses you. (Can also use it during the spam I mentioned before, especially if you're using ethers and such)
All laser patterns he does can be guarded... so just press square.
Beyond that, know that you 'can' reflect that move where he goes "Can you spare a heart?" and it'll stop it from doing anything to you.