The issue was I was fighting them in Hell. And they're all either Cold or Fire immune... I was trying out a Blizzard/Fireball hybrid. Needless to say, half way through the den about a hundred Fallen and those Gargantuan Beasts swarmed me, and I was a glass cannon, so...
You can fill in the lines
(Immunities sucks.)
*slowly raises his hand in the back*