Blackwyrm Cult

The black dragon Nalice hid with her Blackwyrm Cult in the Master's Cellar beneath Karazhan, Medivh's former home and one of the most powerful magical locations on Azeroth, researching arcane secrets buried beneath the foundation to perform some sort of arcane experiments. Rogues seeking to gain the were tasked with going to Karazhan, linking up with Wrathion's agent, then killing Nalice and obtaining a vial of her blood.

Members

 * (leader)

Speculation
With Nalice's death, it is unknown what happened with the cultists. Since they are not present in the Master's Cellar during the third invasion of the Burning Legion, they may have gone somewhere else and hid themselves.