BMFFI: You forget that NUKE is the only offensive spell besides FADE that retains full effectiveness against Chaos. All the others (FIR3, ICE3, LIT3) do laughably little damage. And by the end of the game, it's not two casts; it's typically more like four or five. And White Wizards can cast CUR4 and LIF2, both of which are practically must-haves for the final battle. (Although I did manage to beat the game without a White Mage once. Still had a BM though.)