Zuvassin the Undoer is one of the renegade Chaos Gods, along with Malal and Necoho. He is a meddler, constantly striving to undo the things which others have done and to soil the efforts of others. His brand of Chaos leads him to ensure that nothing turns out as expected, and that all plans will go awry. He does not confine his sabotage to Chaos, but will quite readily spoil anything for anyone; however, because he is a Chaos God who acts against the purest essence of Chaos, he has been classified by human scholars as a ‘renegade’ god. He appears frequently to his followers, donning in a variety of guises, often choosing to take the form of the thing which they fear most, or that of a member of their own race who is horribly disfigured or deformed. No matter what form he takes, he is always laughing.
The symbol of Zuvassin is a double ended Y-shape, which is normally depicted incomplete or otherwise incorrect in some way; some part may be missing, or something may have been added to it.
Zuvassin is the patron of those who desire to use his powers to sabotage or undo something. All those who follow him find their plans going wrong in the process. There are a handful of cults in the Old World devoted to him, and he has been known to usurp cults which think they are worshipping another of the Chaos Gods, in order to revel in the confusion and misery of letting them down. Zuvassin, living up to his title, can undo everything, even removing the taint of Chaos from an individual by removing their mutations.
Zuvassin is an enemy of all of Chaos, even including the other Renegade Gods, but it has been known for him to ally himself with another of the Gods of Chaos in order to thwart another's plans; for example, he might decide to aid the forces of Khorne in conflict with those of Slaanesh, (or vice-versa), if one of the Chaos Gods has a scheme which looks like it can't fail.
Zuvassin will never refuse anyone who is foolish enough to offer him their loyalty; even the most exhaustive of terms will not worry him, as he is confident of being able to make things go wrong if it suits him to do so. Zuvassin imposes no restrictions upon his followers, since any character who is truly imbued with his spirit would be able to make any instructions misfire.
- Zuvassin (along with Necoho the Doubter) was created by Games Workshop writer Graeme Davis to replace Malal in the "Something Rotten In Kislev" campaign for Warhammer Fantasy Roleplay, published in 1988 as part of the "The Enemy Within" campaign.
- Zuvassin is also listed as one of the Chaos Gods in the sourcebook "Tome of Salvation".