Greyskin

Greyskin is an acute effect contracted by direct contact with basilisk poison. Basilisks are extremely rare as they have nearly been hunted to extinction, for their poison.
The basilisk have a poison gland just behind its eyes, just above the nasal region. Two small muscles on either side of the gland, allows the basilisk to squeeze the gland, causing it to shoot the poison out through its eyes via the tear ducts.

Is that lizard squinting at me?

— An unwitting victim of greyskin, a second before infection

Skilled hunters kill the basilisk and carefully extract the poison by draining their glands into non-organic containers. Objects made by leather, or other organic material, will suffer the effects of greyskin immediately.

Transmission & Vectors

Greyskin is noncontagious and can only be contracted by direct contact with basilisk poison. Simply touching the substance is enough.
Some assassins have weaponized basilisk poison by coating arrow or bolt heads with the poison. When the bolt or arrow penetrates the target, the poison will be carried with the blood, spreading through the body at an alarming rate, causing death within minutes.

Causes

Direct contact with basilisk poison will immediately cause infection and start spreading from the point of contact. Any attempts made to wipe away the poison will most likely accelerate the process, as even the slightest smear or droplet will cause greyskin to spread from the affected area.

Symptoms

The condition escalates so quickly that all the stages happen within minutes of touching basilisk poison.

Stage one

The point of contact will immediately start turning grey, and spread outwards so fast that it is perceivable by the human eye. Although the condition is called Greyskin, it is not only the skin that turns grey, but everything, including bones, tissues, and blood.
The discolored tissue will also start to itch almost immediately. The spread continues until the entire body has been infected.

Stage two

The discolored tissue starts to harden and gradually dries up, causing the tissue to become stiff, to the point where it feels like stone.
This process is extremely painful to the victim, especially when internal organs or even bones have become infected.
At this stage, there will be reduced motor control, as the muscle tissue starts getting infected, as well as difficulty breathing, as it spreads to the lungs.

Stage three

At this stage, the victim is in extreme pain, if not already dead, depending on which organs have been infected. All infected tissue has hardened and dried up, and become brittle. A forceful blow will cause the infected tissue to shatter into small fragments.

Stage four

At this point, the victim is dead. The entire body is now fully infected and hardened into an extremely brittle stone-like state. If left untouched, it will eventually disintegrate into extremely fine powdered dust that is easily carried away with the wind.
This last stage is a highly desired effect for assassins, as it practically removes the victim from existence, scattering them with the wind. A perfect kill, with no corpse.

But ... he was right there, I sweat it by the light! He was laying right there, with a bolt in his shoulder.

— A witness showing a murder scene to a city guard

Treatment

The Temple of Light has managed to come up with a cure for this rare condition, but just as the poison is extremely rare, so is the antidote, as it is made from the basilisk poison.
Boiling the poison while mixed with leaves from the clang flower effectively creates a poison that attacks the infected tissue and reverts it to its natural state. This process is slightly slower than the spread of the poison, so the antidote must be applied strategically, in order to effectively block and combat the poison.

Prognosis

If no antidote is given, death is guaranteed. With an antidote, survival is almost guaranteed as long as the patient is not further than stage two.
In stage three, the chances are at least halved, depending on the spread. It is impossible to bring back anyone from stage four, as they're already dead.
It is extremely rare that anyone survives contact with basilisk poison, as the infected are rarely near an antidote.

Prevention

The only way to avoid contracting Greyskin, is to avoid contact with basilisk poison at all cost.

Cultural Reception

The greyskin condition is so rare that some believe it to be a myth. It is also hard to prove the existence, as people that die from it, turns into dust, and survivors able to tell the tale are extremely rare.

Type

Physiological

Origin

Natural

Cycle

Short-term

Rarity

Extremely Rare

Severity

Almost always fatal

Curable

Yes, but the cure is rare