Sorceresses

Elves have a natural affinity for the shifting Winds of Magic. In the ancient days, they learnt the secrets of manipulating this mystical power from the Slann, the most powerful servants of the Old Ones. Yet for all their expertise, there was always a limit to the amount of power the Elves could harness -- the risk of madness and spiritual corruption prevented them from delving deeper into the power of Chaos.

It was Morathi who first ventured into this forbidden territory. Through dark rituals and bloody sacrifices, she moulded the energies of Chaos to her bidding. With this sorcery -- the unrefined power of magic -- Morathi soon began to weave enchantments and spells whose raw power far outstripped anything the Elves had previously known. To this day, Dark Elves study the sorcerous arts, utterly seduced by the unrestrained energy it allows them to command.

Chief amongst the magic-wielders of Naggaroth are the sisters of the Dark Convent of Sorceresses who are gathered in the great fortress of Ghrond. Competition for positions in the Dark Convent is bloody and fierce. Those that survive their sisters' ambitions learn some of the most powerful magic in the world. They can call upon ancient daemonic entities to devour their enemies, hurl storms of wicked shards at their foes or engulf them in dark energy.

Though Dark Elves of both genders are capable of master the art of Dark Magic, male sorcerers are regarded with disdain, fear and suspicion -- a situation only exacerbated by generous bounties Malekith offers for such a being's severed head. The Witch King knows of the Prophecy of Demise, whose ancient stanzas foretell how a great warrior will one day be cast from his home by a sorcerer. Malekith -- ever given to a cautious mindset in such matters -- believes it is he to whom the prophecy refers, and he is determined to cheat that destiny -- one severed head at a time. Nonetheless, there are still those who would rather risk the Witch King's wrath than incur a debt to the Convent of Sorceresses, so some sorcerers yet survive.

Should a Dreadlord's need to be great enough to secure aid from the Dark Convent, however, he will find himself in proxy command of a magical mastery as well-rounded as it is ruthlessly wielded. The Dark Magics of sorcery are but one of the disciplines studied by the Sorceresses of Ghrond, and they can call upon the Lores of Battle Magic with just as much skill as the stiff-souled mages of Ulthuan. Enemies can be immolated by whirling fire storms, turned to crystal by swirling purple energies, torn limb from limb by elementals, blasted apart by lightning or transmuted into solid gold. All the while, the sorceress laughs with wicked delight, her castings becoming wilder as the joy of battle overtakes her. Yet no matter how absorbed she becomes in the destruction, the sorceress always has one eye on her putative employer, her mind ablaze with the possibilities of how she will exact payment if none voluntarily forthcoming.

Source

 * Warhammer Armies: Dark Elves (8th Edition) -- page 37.