Haethen Kaul is the leader of the Twilight's Hammer clan in the Masters' Gate area of Deepholm, hovering in a blue pillar of light in the rocky overlook upon the Twilight Terrace[39.9, 62.1]. He directs his followers in unearthing the waygate that leads to Uldum, paving the way for to enter and claim a powerful titan weapon. Even so, he reminds his followers that they "serve a higher power", presumably the Old Gods.
Haethen is also siphoning the power from several bound elementals imprisoned by his cultists.
Some telling quotes...
- Haethen Kaul yells: It is true that we serve Deathwing, but we also serve a higher power. Never forget that!
- Haethen Kaul yells: The titan Waygate is almost opened. We will assist the Tol'vir to reconfigure Uldum and bring about the end of all life on Azeroth!
- Patch 4.0.3a (2010-11-23): Added