This quest is part of the Hero of the Mag'har quest chain.
Locate a Soul Mirror somewhere in the Auchenai Crypts and use it to call forth a Darkened Spirit from Ancient Orc Ancestors in Nagrand. Destroy 15 Darkened Spirits so that the ancestors may rest in peace.
For several centuries, the spirits of Auchindoun coalesced into my darkened essence. Many of the catastrophes that befell this crypt were a direct result of my weakened state.
Regrettably, there is nothing that can be done to stop this cycle. It is a facet of the naaru condition - without the void, the Light cannot exist.
Your only recourse is to destroy the ancient spirits of Nagrand before they transform into creatures of the void. Use the soul mirrors found throughout this crypt to free them...
<Mother Kashur is visibly upset.>
These naaru are wise beyond all manner of life on this world.
You have completed a long and dangerous journey, risking life and limb to ensure the safety of the Mag'har and the serenity of our ancestors. For this I am thankful beyond what words could convey.
The soul mirror is a purple crystal behind the last boss, slightly to the right.
Some people can solo the Darkened Spirits, most prefer company. Soloing strategies tend towards kiting, and some classes don't kite well. Defeat them with a friend: half the time per kill, half the total kills needed.