Long ago, the whole of the land of Zendelon was untouched by such a phenomena of this form, of decay and darkness, death and sinister thoughtlessness. The Taint was forced into Zendelon when it merged into the material plane with Jashnia, and has been slowly rising to the surface ever since. Its source is unknown, but it is obvious that it is spreading more rapidly now than ever. Because this force effects everything that touches the land in this area, including large portions of Si'ir, many believe that it is a force that is coming from underground, and which cannot infiltrate the element of water. It seeps out from both sides of the Straits of Renshunan, creeping its way up both countries' coastal lands.
Iyo Tisha is the most affected city in the zone, and is completely uninhabited by humans, elves, or any other common humanoid. Nezumi (or Ratfolk), however, are impervious to the Taint's effects, and survive safely without infection, madness, or deadly side effects, as most humanoids experience.