Curse of the Crimson Throne
Blood veil is no natural malady. Created by plague-shaping cultists of Urgathoa who were funded by the Red Mantis, blood veil is a refined form of Vorel’s phage, an unnatural disease that first came into being deep under Foxglove Manor, on Varisia’s coast (see Chapter 2 of Pathfinder Adventure Path: Rise of the Runelords Anniversary Edition). The arcane and alchemical manipulations of these two nefarious organizations have altered the potent necromantic infection into a weaker but more virulent weapon—it no longer creates undead from those it slays, but it is much more contagious and difficult to recover from.
Blood veil takes its name from its most apparent symptoms: a rash and mask of blisters that cover the face. In its initial stages, the disease is characterized by headache, fatigue, coughing, and the aforementioned rash. As it progresses, the cough becomes more obtrusive; the rash spreads to the neck, face, and limbs and develops into poxlike blisters; and the lymph glands swell into painful buboes. At its most advanced stage, the blisters grow to the size of grapes or larger, internal bleeding creates black patches on the skin, and the victim expectorates blood. Ultimately, a bloody, wheezing death occurs. If left untreated, blood veil kills the average human in 7 days.