Urien Rakarth

"'Casket of Flensing, vile souls within, come out, COME OUT, and remove his SKIN!'"Urien Rakarth is a Master Haemonculus and the concept of torture made flesh.

Official Canon
Rakarth is a depraved genius who has lived since before the Fall of the Eldar Empire. As a Master Haemonculus, his knowledge and skill in the crafting of flesh is unmatched. He is the progenitor of the regeneration process used by all Haemonculi to revive Dark Eldar. He has died and been resurrected multiple times and now savors death like a fine wine. At some point his regeneration process was corrupted, and now Rakarth gains a new vestigial part with each reincarnation. He has transcended the political squabbles of Commorragh and now lives only to revel in depravity.

TTS Canon
Rakarth is first seen accompanying Asdrubael Vect during his meeting with the Star Child. At an unknown point, Rakarth planted spyware in the Imperial Palace, a fact which enrages Rogal Dorn.

Rakarth explains that torturing the Star Child will protect all the Drukhari in Commorragh from Slaanesh. He proceeds to try various torture methods, all of which fail. When Vect begins feeling genuine happiness, Rakarth realizes that the Star Child is emitting an "anti-negative energy." Various torture methods are attempted, but the Star Child remains unaffected, and his energy begins affecting Rakarth and eventually the rest of Commorragh.

Rakarth is revived and strengthened when Vect manages to undo the Star Child's anti-negative energy. When the Star Child tries to leave and search for his companions, Rakarth uses a Necromantic Depravator to suppress his powers and keep him trapped.