The Katarai Gene

The Katarai Gene is a genetic trait which occurs in all lifeforms on Earth, but most prominently Humans. Humans with this trait are generally referred to as Katarai. The Katarai gene is always hereditary, Dominant and incurable. This mutation causes the Disconnect between the Mind and Tulpa to be less severe, with a few consequeces.
Katarai are naturally more adept at Tulpathy, but more vulnerable to Demonic Reversal. Constant Tulpa activity causes physical mutation in the body over time. The older a Katarai gets, the more noticeable these mutations will be. Neither the Mind nor the Tulpa are actively responsible for this. Katarai mutations are often described as extremely painful and can become life threatening to the mutated individual. Most afflicted die before the age of 40 without proper medical aid.

It is often mistaken to be an infectious affliction, as those in prolonged close contact with a Katarai will exhibit similar mutation patterns. However, those who gain mutation through contact do not have the Katarai gene and will not pass it on to offspring.
The gene is rare, but has occurred separately at least 5 times in humans alone. Each instance of it evolving has led to wildly different mutation patterns.
Due to the associated mutations, Katarai were often ostracized when discovered. They were viewed as impure, sinners, devil worshippers, monsters, devils... Because of this, Katarai families often secluded themselves to avoid lynchings. This led to accusations of inbreeding and further excluded Katarai from society at large.
Late Medieval genocide campaigns by the Lunar Pact drove them off the overworld. What remained of them gathered in Surface caverns known as Refugia.

Type

Genetic