Old Gods

The Old Gods are the most powerful and evil entities in existence. There are rumors of their figurative hands being in pretty much any disastrous event that has ever occured across the cosmos. However, most beings aren't even aware of their existence.

History
At times, they have attempted to use Illidan Stormrage and Sargeras as their pawns. They also successfully put Neltharion the Black under their control, warping him into Deathwing the Destroyer. It is ultimately the Old Gods who coerce Blackriver into becoming Deathwing's apprentice.