The Black Madness
From Lost Fables Wiki
The cultists of Grytuss the Black are sometimes, through the Dream, gifted a ritual of Truth which allows them to inflict some sliver of their Mad Deity’s mental scarring onto the world. When performed, a thick, sickly, greenish-white fog rolls out from the ritual site, covering an area a kilometer around for as long as the chosen sacrifice’s life force holds up, usually only a week or so. Multiple rituals expand this fog, but also drain the life energy of all sacrifices within much faster. At the longest, the sacrifice can hold out for a week before turning to dust, while each additional ritual to expand the Mists lowers this by two days, meaning that at a four kilometer diameter, the Mist will only last a day. In order to qualify for becoming a sacrifice, a person must already know and have used a Truth, and thus Mist Men are unsuitable.
Infection can only occur through breathing the mist for an extended time.
It can only be created through rituals, or transported from the Volcanic Island
After spending upwards of an hour in the Mist, an affected person’s perceptions will begin to alter. They’ll start to hear distant, terrifying noises, and small flashes of light will be seen in the distance in the mist. Given another five hours, once the fungus has built in the lungs enough, there is a sudden “breaking point,” wherein the person’s soul is suddenly severed from its connection to the body and consumed by Grytuss in a flash of burning, radiant light pulsing from inside the subject’s skull. Just like that, the subject becomes a Mist Man, their mind gone, replaced by a husk which lives only to serve Grytuss, attacking people in the Mist and attempting to trap them until they themselves become a Mist Man. Some people, more or less randomly, seem to be immune to the fungal infection, though it is unknown why, with the exception that “sane” loyal followers of Grytuss seem to be immune to its effects in order to further spread the Mists. In addition, those who know and use Truths are immunized.
If you begin to experience hallucinations in the mist, leave, or your personality will perish, your soul consumed by the God of Madness
The only cure once one has become a Mist Man is a merciful death.