This quest is not available in game.
Find the three gemstones of command: The Gemstone of Smolderthorn, Gemstone of Spirestone, and Gemstone of Bloodaxe. Return them, along with the Unadorned Seal of Ascension, to Vaelan.
The Generals, as told to you by Vaelan, are: War Master Voone of the Smolderthorn; Highlord Omokk of the Spirestone; and Overlord Wyrmthalak of the Bloodaxe.
As you can see, the unadorned seal has three empty sockets. Each of those sockets must be filled with a gemstone representing the leadership's command. Finally, Overlord Wyrmthalak, master of the lower citadel, must forge the seal in the flames of the Black Dragonflight.
Understand this, mortal: the chance that one of the three generals of the lower citadel would carry a gemstone at any given time is rare. You must be vigilant in your quest. Remain determined!