Rygax

"I've only lived this long by weighing each risk against the desperation of the cause, and I'd say we're nowhere near that desperate... yet." - Rygax
Rygax is a powerful half-Eladrin priest of Ankou who resides somewhere in the Shadowfel. He led a partially successful rebellion against the vampire king Vladimir and also slew one of the previous holders of the title Baron Deathmoor. Unlike the traditional Elven "German" accent, Rygax's voice is reminiscent of Sir David Attenborough's.
He has spent the past few years hiding from Swayne, not even contacting the Shepherds. At one point he travelled with William Black (who he refers to by his middle name of Gabriel), but this of course ended when Black sr. was captured by the aforesaid Vampire. After torturing the locations of some of Rygax's hideouts from him, Swayne kept him around as bait for a trap, later adding Zaheer to his collection.
When the party rescure his captives from Mount Pillar, Swayne intervenes personally and it is only due to Rygax's intervention that they are not completely wiped out. He later recounts the tragedy of Balvan the Wise Millstone, implying a good deal of Shadowfel knowledge.
Rygax allows a colony of Mezania to live in two fingers of his left hand. This has given him the ability to converse with other Mezania colonies around the Shadowfel, acting as an information network.
=== Archon form ===
Rygax has the power to assume an "archon form", effectively becoming a divine avatar of Ankou. The exact powers this gives him are unknown, but if episode 60 is anything to go by, it involves projecting rays of light in combat.
Each use of this power costs him about 1/3 of his life force, which is the reason he is currently much weaker than in legend. He has so far used it twice, the second time being to clear the path to Vladimir during the rebellion. It is unknown why he used it the first time or what he achieved.