Copied from Masamune 1600's answer:


(Fire)=(Quadra Magic) (Fire)=(HP Absorb) (Fire)=(MP Absorb) (Fire)=(Added Cut)

(Fire)=(Magic Counter) (Fire)=(Steal as Well) (Fire)=(MP Turbo) (W-Magic) (Magic Plus)

It's a very nice combo. Of course, you can do it not only with Fire, but with every magic that can be Quadra-Magic-ed. But believe me, it's not like you will need to do it with something more powerful, even at the end of the game.