The Overseer

The Overseer is the title given to a mysterious being on the Plane of Shadow. They have powerful magical capabilities, being able to teleport at will. They claim to be a double agent of Hell's Legion, and is working towards destroying the 9 Gates of Hell. Most likely, this is a ruse, as Drogol Sharkfiend claims that the Overseer is searching for the Elemental Amulets in an attempt to rewrite reality.

They wear a mask and black robes, with a hood.

The Overseer apparently killed Drogol Sharkfiend in an ambush plotted by the Blood Red Revenants, however, the cyclops somehow managed to survive.

Trivia

 * The Overseer is inspired by the Norse god Loki.