Chaos Sorcerer

The Sorcerers of Chaos are powerful spellcasters who use the raw Winds of Magic to cast spells. Masters of Dark Magic, there is little beyond their might. They can transport themselves over vast distances, call upon the fires of Tzeentch, slaughter men by the scores, and more. But such magic comes at a terrible price. As they tap the energies of Chaos, their sanity withers whilst their bodies twist and mutate with the invoked energies.

Chaos Sorcerers may be found amongst the savage tribes of the north, serving as oracles and counsellors, but many also come from the lands of the Empire and beyond. These individuals, finding the limitations on magic within the Colleges too restrictive, and lured by the power to be held by dabbling in Daemonology, drift north to bring themselves closer to the source of their magic, learning through trial and error.

What separates Chaos Sorcerers from other spellcasters, namely the Magisters of the Empire, Witches, and Warlocks, is that these individuals derive their power directly from their Gods. So, only servants of Nurgle, Slaanesh, and Tzeentch may become Chaos Sorcerers (Khorne abhors magic).

Types of Sorcerer

 * Maledictors are Shamans and Witch Doctors, minor spellcasters at best. They dabble in the dark arts, but have little understanding of what it is that they do. A few join a warband in the hopes of gaining a better understanding of the nature of Chaos.
 * Doomweavers are distinct from the lesser Chaos Sorcerers because of their deeper understanding of the workings of magic. These spellcasters select one Chaos patron to serve, and draw upon magic as granted by this profane God. Doomweavers advise Chaos Champions, or at least, bind themselves to a powerful warlord.
 * Soulflayers barely resemble their former selves, as they are riddled with mutations. These individuals are warped by the magic they wield, becoming both more and less than what they were. Mighty spellcasters, Soulflayers are among the most potent servants of Chaos, eclipsed only by the Cataclysts. Most Soulflayers may command a coven of Maledictors, instructing them in the arts of Dark Magic.
 * Cataclysts rival the Exalted Champions of Chaos in sheer magnitude. They can conjure up the most profane Daemons and level legions with their corrupt energy, becoming living vessels of the raw energy of Chaos. Their minds are blasted by the experiences they have endured, and they are mere shadows of their former selves. Cataclysts always employ Daemons to do their bidding and are valued members of any Chaos Horde.

Source

 * Warhammer Fantasy RPG 2nd ED -- Tome of Corruption (pg. 165-167)