Ereth Khial

Also known as the Pale Queen, Ereth Khial is the supreme goddess of the Underworld. Long ago she attempted to seduce Asuryan and, when he resisted her, she grew enraged, stole the souls of the dead and hid them in the black pit, Mirai. The Pale Queen has never forgotten Asuryan's slight. Whilst he lies beyond her power, the Elves do not, so it is they who suffer Ereth Khial's wrath. Should a waystone be destroyed, Ereth Khial sends the wraith-like rephallim to seize what souls they may, and bear them away to dwell in Mirai in eternal torment. Such thievery must be quick, for Slaanesh, the Dark Prince of Chaos, suffers no one -- not even the Pale Queen -- to take even the meanest of scraps from his table.

Ereth Khial's deeds may have made her outcast from Asuryan's court, but many of the Elves' darker deities acknowledge her as their mistress. Even so, she is seldom worshipped in Ulthuan. Most folk do not entreat Ereth Khial's blessings but hope to avoid her attention altogether, wearing sprigs of wyrdroot or blackhame to avert her vengeful gaze. Some Elves, however, think it better for their spirits to endure eternity in torment, rather than meet oblivion through Slaanesh's hunger, and thus secretly court the Pale Queen's fickle favour.

Such obsessions must perforce be kept secret, for the worship of Ereth Khial is widely considered the sign of a diseased or ill-adjusted mind. Those marked by the Pale Queen's touch are inevitably exiled or imprisoned should their terrible secrets be laid bare, yet her priests and celebrants have never been entirely eradicated from Ulthuan's shores.

Source

 * Warhammer Armies: High Elves 8th ED -- pg. 45