The Dark Mist and Sendrils

The Dark Mist is the type of mist that shows up during the period of darkness after the Old God falls asleep. Logos is its source and located somewhere in the sea. The Mist itself isn’t really harmful I believe, but the thing is that it brings the Sendril with it.

The Sendril/sendrils are wormlike creatures: “People used to regard the Sendril as a kind of toxin until someone isolated the Active Sendril from the corpses of the Marred monsters. From then on, it was clear that the Sendril themselves are a kind of living creatures.” - from the Active Sendril’s description.

While inside some strong Marred, sendrils immediately integrate with them and form active symbiotes. It is extremely contagious, spreading when contaminated corpses are touched. Not only animals or people, even non-living objects can be contaminated as well.

Inside some Marred, couriers can also find Immundi and Blackwater crystals. Immundi solidify in the host body when their energy is consumed by the Sendril. The better the quality of the Immundi found, the more contaminated its host was (from Immundi descriptions). Blackwater Crystals are formed in the Marred when they are exposed to the light of the Colossi which leads to the body fluids of the Marred solidifying. The stronger the Marred monster, the better the quality of the Crystal that is found (from Blackwater Crystal descriptions).

From the Secret Records we can actually understand the nature of contamination by sendrils and its effect on human bodies:

1. In the earliest stages a person remains in a weakened state and gets tired quickly; Slowly loses the ability to walk on their own.
2. Later comes the constant pain in the whole body, so the person refuses to eat or drink and becomes lethargic for a long periods of time. When awake, usually hallucinates;
3. The skin starts to ulcerate and a black smoke rises from the contaminated body. The pain intensifies and a person falls into a coma;
4. The body starts to rot, the pain becomes completely unbearable;
5. Transforming into a Marred.

Besides, it seems like the decomposition can be caused by the toxin sendrils produce (the Poison Awl description) and in the early stages it can be partially suppressed by bloodlettings (as it lowers the concentration of this toxin in blood) and some medicines. If measures are taken immediately, a contaminated person can live for some time (like Higgins held out 15 years).

I’m really curious how sendrils are generally viewed as a deadly contamination, but descriptions above and also this description of the Cursed Hood imply that if a creature is strong enough to survive the contamination, not only it won’t die, but also will keep some kind of consciousness: “After the falling of their Colossus, the Disciples could only wander in the Dark Mist in search of the next one. They ate everything to survive… When they found the next Colossus, they hated the light and forgot why they were exiled and what they did. This is the curse of the Dark Mist, they have already become the Marred”.

That can explain the existence of Nightwalkers - people born already contaminated from Marred (one of them is Jerold).

This also explains the way some tribes are still living in the Mist and maintaining their own primitive culture (if we can call it culture). From the Mist Bracer’s description: “Crafted with Pagan sorcery, this bracer is imbued with the power of the Sendril. To protect themselves from the bloody purges of the Church, the Pagans united believers from different tribes to develop rituals to use the Sendril to enhance combat power”.

From those descriptions we can also understand that there’s a direct confrontation between the Pagans and the Church as the Church even has a whole Heretic Tribunal to deal with them.

A curious detail: it seems that, unlike human beings, animals don’t go through this bloody hell of contamination and usually survive it, though their bodies undergo significant changes. For example, Dryad Lizards and Woodspirits become venomous, Deers get new gleaming antlers that make people who stare at them go mad and so on.

Besides, every type of Marred seems to have its own weaknesses like, oddly enough, some are afraid of the Sendril toxin or fire or the Soul River Water or, obviously, the Colossi light.