It all come down to this. Ratbag has tracked the real Ranger to his real holding place in Gorgoroth. Follow him to the spot.
Once there, your goal is the sneak in without raising the alarm. Note that this doesn't mean undetected, just that the call never goes up.
Of course, the easiest way to ensure silence is stealth-killing everything in your path. Use Wraith Vision to scout your targets, then sneak and destroy.
If you are detected, use your bow to silence the witnesses before they can run for help. Continue this pattern until you reach Ranger, chained up behind a building on the far side of the camp. Luckily there is no one guarding him at present.
You'll free him in a cutscene. When that's done, follow him to Bruz, who has gained a few levels since we saw him last.
Now you and Ranger face off against Bruz and his minions. Bruz is much more powerful than Ranger, so you'll probably be doing a certain amount of first aid here.
No matter- Ranger's main strength is that he can keep Bruz occupied while you attack from behind. Daze him, and you can ride him into the near explosive barrels (doing this three times is your bonus objective).
When he's broken, go ahead and use the Stare on him, but there's only one option left.
Not only does this reduce Bruz to a babbling, broken, brain-damaged husk of his former self, it also unlocks this power permanently, allowing you to magically lobotomize any captain you Dominate. Because your mind control wasn't creepy enough.
In any case, with Bruz' descent into forced dementia, this mission and questline are over.
