His men feared him more than the enemy, as he was known to kill any of his own men who tried to run from battle. Every man was expected to draw blood. This involved no small amount of planning, since he was almost always outnumbered. First with the most if he were a powerlifter, he would have squatted aggressively holding nothing in reserve. So far, so good.
Image is everything.
Some consumed mushrooms and other drugs, chewed on their own battle shields, and moaned and shrieked during battle. Yes, they were basically normal and well-adjusted powerlifters. The point is, this strange behavior trained their opponents to fear them on sight particularly important to them in their role of initial strike forces. Even more salient, they trained themselves to think they were tougher than they actually were. They were mortal, and they died in battle quite often.