Thanks for the laugh, guys !

By Mouse
I absolutely refuse to ask what happens next!!!
*with a grim and deep, whistling voice* You asked, and then, shall be answered... there is no coming back !

The Nyctis are partly plants (using light, warmth and soil nutriments, producing oxygen) when adults, even if they can move with the winds and (with less efficiency) on the ground, to find a better place to grow (more like animals, a bit like an airy plankton). Their spores are the danger. It's very small and enter the body by any possible natural entrance, hence the necessary protection of the head and the checking of possible injuries. Once in the body, it first works as a virus : penetrating the cells, the spores are replicating themselves. This "disease" is called "Endymiosis".
At some point, the victim is partly hallucinating, with possible visual or sound that tends to lead him outside of the cities, looking for cold. It's called "Call or song of Persephone". If not stopped, the weakened victim often dies outside and form the "rich soil" where the stock of spores is growing, becoming new Nyctis, quickly forming a moss wherein the remnants of the body is less and less recognizable.
It's a true terror in the cities, where environment is controlled... and where a contaminated subject could spread spores easily by cough...

About Stygian Larvae : those larvae are seeking the body warmth and generally ends in the digestive system. They are nesting there, attached to the intestine wall and interacting with some parts of the body. The poor victim is first acting like a rabid victim... then goes to weakness. Some toxins produced by the larvae when they've grown, are affecting the body, causing cell death and putrefaction, starting with skin and going inward.
Considering the symptoms, they are often seen like zombies. Useless to say that someone with a foul stench or a strange skin is generally not welcome... Adult, it looks like a big centipede and eat trange acari and mites.