Okay king of all key holes. This might be useful. On your Quick command magic spells put: Cure, Areo and Gravity. (Obviously by this point they will mostly be at their highest level) Basically all you need to do is target the Invincibles then use Gravija on them which will lessen their HP significantly then slash away. Maybe use Gravija twice. Also Cure occaisonally and if necessary use Areo to protect. Makes sure you equip abilities that will help you maintain your MP for spell casting. *forgets the name of specific abilities*