Mazza-Mirri and Shando-ri
The Order of the Hidden Moon was an ancient Khajiit order dedicated to Azurah, based in what became the Ashen Scar. They were responsible for dealing with the Dro-m'Athra, by using a form of necromancy which would allow the dark spirits to redeem their corrupted souls and to pass through The Crossing. The Moonlight Blade was the special weapon of their order, blessed by Azurah herself.
At some point in the First Era, a schism occurred when one of its adepts, Arum-Khal grew dissatisfied, renouncing Azurah and sought to take power for himself. Many of his fellow adepts followed him and the resulting civil war destroyed much of the temple complex and surrounding area. The survivors were unable to slay the now-lich Arum-Khal and instead sealed his spirit within the crypts. The Order became a memory and legend, until the time around 2E 582, where Arum-Khal's awakening caused the undead of the Ashen Scar to rise as well. However, some spirits of the Order still remain in the ruins, ready to stop the powerful Dro-m'Athra Lich once and for all.
Remnants of the Order can be found in other places around Northern Elsweyr, such as the Nightmare Plateau, a former Hidden Moon shrine where the Dro-m'Athra Zalsheem was sealed.