Kill the Shadow Council! (Horde)

Objectives
Kill 10 Shadowy Executioners, 10 Shadowy Summoners and Shadowmaster Grieve, and then return to Advisor Faila at Stonebreaker Hold in Terokkar Forest.
 * slain (10)
 * slain (10)
 * slain

Description
What! Those guys are Shadow Council?! &lt;name&gt;, you have to go back in there and waste them! I want you to take out their leader and as many of their executioners and summoners as you can. After you're done with that, report back to Advisor Faila at Stonebreaker Hold. Good luck, &lt;class&gt;!

Reward
You will also receive:

Completion
That is unfortunate news! But, of course, I made the right choice in sending you out there to help Neftis. The last thing that we need is the Shadow Council establishing a strong point right on our doorstep! &lt;name&gt;, you've earned yourself something nice. Go ahead, take your pick.

Gains
Upon completion of this quest you will gain:
 * 13750 XP (or at level 70)