It doesn't have to be clever, It doesn't have to be balanced, it just to to be something you think is you think would be neat to have in the game...If its clever and/or balanced all the better...
let me get the ball rolling:
Cost: x (orc) (orc) (orc) (orc)
Title: Oi! get to stomping!
Effect: search your deck for any number of units with the sum converted cost of x.
Ok, now you try!
He bested the heroes, killed the defenders, overtook the world. Then he killed the narrator and he was the villain no more.