Nigni

Nigni (singular Nign) are corrupted Archons, who survive by devouring Souls from the inside, after seeding themselves there by posessing them in a dream. It takes one day per layer for a soul to be devoured, and when it is, the eyes turn red, and the Nign takes control of the body, taking five hours for the body to die, in the first hour, the bone marow is turned to ash, then in the next the bones char, and singe the flesh around them, in the next, the iron in the blood is turned to arsenic, causing internal bleeding in the eyes which turnes them red, in the next all bodily fluids gain acidity equal to that of sulfuric acid, and start dissolving the flesh, and in the final hour, all bodily fluids, and bone become white hot, turning everything else to ash, and burnt flesh. If a Nign dosn't devourr a soul in three months, it dies, the resulting death causing a plauge. the Black Death, Influensa, Sars, and Ebola were all caused by the death of a Nign.