Umm...ain't there like two or three other topics for this?
Just don't change all of your party members out of being zombified. Unless they got Regen on them, leave them as a zombie. When I did it, after I had everybody come up and take a shot so they could get the AP, I had Tidus, Wakka, and Auron (my physically strongest set) fighting her, and Tidus had Auto Med on his armor, so every time he was Zombified, he healed himself.
