We can't really take a good look at Garrosh Hellscream without taking a look at his Alliance counterpart, King Varian Wrynn. Varian is an enigma in his own right, although for different reasons than Garrosh. Where Garrosh was a character that was introduced and shown in every aspect in the game itself, Varian is notable for being ... absent. He wasn't there for vanilla WoW. He wasn't there for Burning Crusade. Varian didn't make his first appearance in game until the launch event for Wrath of the Lich King, and exploded onto the scene with an attitude that threw a lot of players off.
Where Garrosh saw all of his development play out in-game, even the odd disconnected moments, Varian saw his play out through a series of comics and novels. Most of his history is a big question mark to many players. While not quite as big an unknown as Lor'themar Theron, people still wonder -- who is this guy? Where did he come from, and why was he so angry when he returned? And perhaps most importantly -- where did he turn from angry leader in the Ulduar cinematic to the far more patient leader we're seeing in Mists?
Oddly enough, his story and Garrosh's mirror each other far more than you'd think.