The Burning Legion attempted to invade Draenor through Auchindoun, devouring the souls of deceased draenei resting within the mausoleum. The preparations for this event began in Shadowmoon Valley, where Exarch Othaar intended to cripple the Council of Exarchs from within through internal strife, with Soulbinder Nyami acting as his subordinate. When the conspiracy was exposed, Othaar revealed his true identity as an eredar: Socrethar, claiming that Velen has betrayed his own people.
Later it is discovered that Socrethar and his Sargerei cult is in league with the Shadow Council and intends to summon the Burning Legion in Auchindoun, following Archimonde's orders. The plan is uncovered and the coalition forces battle the Council forces around Talador, and later are lured to Xandros, a destroyed world where the pit lord Mongrethod resides. They manage to defeat him, but not before Nyami penetrates the defenses of Auchindoun and allows the Legion to enter the mausoleum.
The adventurers and Soulbinder Tuulani team up to push back the invading Legion forces inside Auchindoun itself. There, Nyami's treachery is revealed and she incapacitates Tuulani before unleashing Kaathar upon the adventurers while the Sargerei hidden within the mausoleum slay its Auchenai protectors. Once the vigilant is defeated, Tuulani rallies those who remain loyal while the adventurers proceed to finally slay Nyami. With the entrance area secured by the Auchenai, the adventurers advance eastward and have to fight their way through several demons that bombard their way inside Auchindoun until Azzakel arrives from Argus; he is promptly defeated.
At the Congregation of Souls in northern Auchindoun, Teron'gor exterminates an Auchenai party while more warlocks from the council arrive via portals. The adventurers enter the area shortly afterward, slay the warlock reinforcements, and confront Teron'gor himself, but during the battle, he ends up blasted off the plateau while attempting to harvest more souls. He is then presumed deceased, which brings an end to the confrontation.