Draigo. He was one of the toughest (if not the toughest) beatstick characters in the game, pre-sixth, and beatstick characters got helped out significantly by the challenge rules. Similarly, Look out Sir! makes him pretty awesome in a unit of Paladins, able to suck up potentially all of the armour-punching, instant-death inflicting wounds the unit takes.
He was good and he got a little better. The army he let you bring was good, and it stayed good. I think he deserves mention as one of the top end special characters in the game. Also, he's awesome.