Zeth'tunnoth

Zeth'tunnoth is a chaotic/evil god from the abyss.

Biology

Zeth is a god with little influence on the mortal plane. It is unclear what its true form looks like but if we're basing it off the results it has on the regular world, it can't be pretty. Zeth moves through the world by infecting creatures as hosts. It appears the infection starts at the soul of a creature, destroying it in the process and replacing it with the soul of Zeth. As it is unable to leave the abyss at this moment. Its influence on the world started when a group of cultists opened a small portal to the layer of the abyss where Zeth resides.
Zeth infected one of the cultists with Marked Dead and used that cultist to spread his influence over Neisloch.

Motivation

As of this moment, the only motivation Zeth has is to spread his influence over the world.