Zarakynel

Zarakynel is a Greater Daemon of Slaanesh, known as a Keeper of Secrets.

History
Zarakynel (also known as the Bringer of Torments, the Souleater, Unholy One and Angel of Despair) is the most favoured servant of the Lord of Pleasure, exalted above any other Keeper of Secrets. Summoned from the darkest recesses of the human psyche, Zarakynel was bestowed Daemonhood as Slaanesh's perfect creation. Known also as the Souleater (as the Eldar Farseers have named this Keeper of Secrets), Zarakynel is the physical representation of man's repressed emotions of jealousy, sadistic pleasure and carnal desires. This potent mix contributed in the creation of the Dark Prince's most feared and prolific killer. Eldar legends speak of Zarakynel preying upon their race several times throughout their long and troubled history. The Greater Daemon has ravaged several Exodite worlds on multiple occasions, slaughtering their kin and feasting upon their Spirit Stones, condemning them to eternal torment at the whims of her dark patron Slaanesh. In battle, Zarakynel wields the dreaded daemonic weapon the Souleater, a long slender blade of terrible power, which thirsts for souls of the innocent.

Source

 * Imperial Armour Update (2006)
 * Imperial Armour - Apocalypse, p. 97