Shadow Rot

When the noble houses retreated from the common areas of Kunrai to the higher, and theoretically safer, canton spires, they left behind many things the lower classes found useful. Some of their gifts, the enormous predictive orreries and stores of alchemical lanters, for example, proved quite useful. Others, however, were far more insidious and dire.
Chief among the dangers left behind when the nobility fled were their stores of effluvia created by their wanton distillation of Radiance. The foul liquid was usually stored in wooden casks and then later disposed of by sinking them into the Strangling Sea. With no one left to dispose of them, the waste containers eventually rotted and their dangerous contents leaked out into the city proper.
Those exposed to the radiant waste often suffer chills and fever, followed by several days of lassitude. Until their bodies can purge themselves of the taint, these poor souls will refuse food, drink water only grudgingly, and have been known to be come violently irritable. In roughly a tenth of the cases, the effluvia leads to a wasting sickness and, eventually, death.
In a smaller number of cases, perhaps one in five hundred, the individual contracts the much more dangerous shadow rot.
This horrible disease has the opposite effect to most effluvia exposure. The afflicted are filled with energy, possess a very upbeat outlook, and become very creative and motivated. This phase of the disease lasts for several weeks, after which the real horror begins.The terrible truth of shadow rot is that it consumes the radiance within the infected. When all of the sacred energy within the sick person is gone, they suffer a rapid, horrifying decline in mental and physical health.
In the first stages of the descent, the sick lose their fingernails and hair. Their teeth become loose in their sockets, and they complain of phantom noises and strange visions. If provided with regular infusions of distilled radiance, the subject will improve for a short time.
A week after the descent begins, the afflicted experience terrible joint pain, insatiable thirst, and become capable of seeing the radiant energy in the spirits of those around them. Radiant infusions can still help stall the disease's progression, but no longer improve the patient's condition. As the days pass, it requires increasing amounts of radiance to provide any benefit at all.
During the second week of their descent, patients become extremely violent and will attack anyone who comes within arm's reach. Those who fall victim to a shadow rotter are slain in horrible ways, and their radiance is consumed. Any patient who kills and devours the radiance of another mortal is transformed into a horrible creature that can only subsist on the energy of living creatures.
No patient can survive more than two weeks of the shadow rot. Most priests or physicians will perform a mercy killing before the disease's progression reaches its natural, grisly end.