The original Dark Conclave was a group of arakkoa which resided in Shadowmoon Valley in the years prior to the First War. The Dark Conclave set up two encampments, Sketh'lon Wreckage and Sketh'lon Base Camp, in the area. When Gul'dan rallied the First Horde, the arakkoa decided to strike against him. However, Gul'dan - having been taught the secrets of the arcane by the eredar lord Kil'jaeden - unleashed powerful magics against the arakkoa, destroying their encampments. Gul'dan's powerful spells made the Dark Conclave arakkoa into ghosts, left to wander throughout their ruined encampments.
Despite Gul'dan's spellwork, Dark Conclave agents continue with their plans to this day. At the Sketh'lon Base Camp east of Wildhammer Stronghold, they are attempting to summon a powerful being of death and destruction, believed to have been a last ditch effort to oppose Gul'dan. However, Gul'dan's spellwork augmented the powers that would allow them to summon this creature - whose appearance is similar to the Old God C'Thun - into Outland. Parshah, an arakkoa who deserted the Conclave, is attempting to gather powerful magic items in order to disrupt the Conclave's summoning.
One of the lords of the Dark Conclave was the arakkoa known as Asghar.