Here you will find some tips and a video that will make it easier, at least I hope, to unlock the achievement.
So, let's start looking for
Intel on a
Warchief.
I recommend
Tumhorn, the requirements to make him appear are simple and also you won't have to waste time fighting him because he can
stealth branded.
Grab also some Uruks and use them to send
death threats to
some Captains.
Once you find
Tumhorn start his mission, free the
Caragors and once the Warchief appears, wait for him to pass near you to
Stealth Brand him with
+
.
At the end of the mission grab him and start a riot against another Warchief (choose someone with some bodyguards).
If the next is
Zugor, hit with ranged attacks and try to take him out as soon as possible, otherwise he could kill
Tumhorn or even you.
For all other
Warchiefs use a
Graug if possible, the video shows where to find bait to lure these beasts.
For each riot choose the
Warchief with the most
Captains as his
bodyguards and when you face them make sure that
one of the Captains remains alive and becomes a
new Warchief.
This way the new Warchief will get at least 2 new bodyguards.
In short:
1- toss a riot at a
Warchief who has bodyguards,
2- hit the
Graug Bait,
3- ride the
Graug (
+
) and use it to
kill all except one of the captains,
4-
kill the rival Warchief.
5- Let the surviving captain escape,
6- kill the Graug
+
(extra points earned)
7- grab
Tumhorn and launch a new riot.
8- Before you teleport to new location, grab Uruks to
send death threats to some
captains (Optional, not all need to be marked).
9-
Repeat point 1 to 8 until all Captains and Warchief are killed.
Note: 1- If there is no bait for Graug just defeat the rival Warchief and ignore the Captains/bodyguards.
2- if the next riot is near or in the same spot as before, you should use Fast travel, in order to make Graug baits respawn.