well, finally i defeated Terra, Rosalina and Xion with the precious Oathkeeper she gives 2 times more lol.
Is there any other quest after this?
Also, to be honest, the more unballanced fights of all the game (i played content version) are in my opinion the ones with the witches in Mushroom Kingdom (BTW, from which game are they???), the team battle i died a lot of times before finally defeat her and the other fight with each individual character was the hellish battle of all the game (for me is harder, very much harder than Rosalina and friends)