This is an important quest since it gives you the power to dominate captains and warchiefs. During my first play through I made the mistake of "captain hunting" before this mission not realizing that I was unable to dominate them like in the first game. Once I discovered this mission I got to work on the objectives.

Finally I can dominate a captain and start controlling armies for my march forward towards victory. A few mistakes I make during this video should be obvious, the biggest one is NOT combat dominating other orcs for health. When your might is full it should be second nature for you to do this simply by pressing X+O on your controller. This method is quick and tilts the odds in your favor as you eliminate an orc, gain health and now there is another fighter on your side that can kill other orcs or at the very least distract enemies to take the heat off of you as you try to wear down Bruz.

In order to get 100% on this quest you need to dodge Bruz's attacks by sliding under his legs when he strikes. It's simple enough since the game will prompt you when it's time. Just remember not to try and leap over him since he can block that and throw you to the ground resulting in additional attacks.