I'm being attacked by a lady made of fire, who is swinging swords made of fire in a volcano full of fire! Oh no, she's throwing fire! What kind of magic spell to use? Duhhh... fire?
If you specialize in one type, you're never able to really know all the strengths and weaknesses.
Sam: Dean, always with the scissors.
Dean: Shut up, shut up, two out of three! (picks scissors again) God!