From my personal experience, my lizard pyromancer is a one-man wrecking crew. A heap of intelligence, a helping of memory, and a dash of constitution for a shield makes him impossible to break through as well. Elemental affinity lets him use his one-AP fire breath to make a fire surface, and "the pawn" allows him to then walk in it for free. Then other spells become one AP as well.
I'm certain I could find comparable builds in melee, but this one just jumped out to me immediately. I do approve of it.
