Repeat prolonged exposure to Vitriol Magic warps the land around the exposure site per the Third Law of Magic, morphing plants and creatures into manifestations of the darkness. The higher the exposure levels at the origin site the further the darkness will spread, although the actual spread takes some time to gain momentum in the early stages. Once the Calamity begins to spread it is too late to save the surrounding land from the change.
The plants and animals dwelling within the affected area change with the Calamity. Harmless plants become hostile and even carnivorous, while other creatures take on rotted or nightmarish properties. Many creatures do not survive the change so decaying plant and animal life is common in the immediate aftermath, while fields of dead trees are a typical warning of the state of the land long past the initial event.
No cure has been discovered for the Calamity. Research efforts are underway to test the effects of fields of Imperial Night Rose upon Kogal Island. Predictions as to the program's success range from hope the flowers will pull the effects of Vitriol Magic from the environment to fear the malamancy will corrupt the flowers and potentially release a new horror upon Fillimet. The malace within areas affected by the Calamity has been known to impact any creature wandering within the area. Those suffering from Unattunable Disorder are the only exception, as the Calamity is entirely magical in nature and the Unattunable are immune to all magic and its direct effects, although any wildlife in the area would still pose a direct physical threat.
Cities must be vigilant in weeding out those who tap into Vitriol Magic, both within the town limits and in the local areas. The best way to prevent the Calamity is to limit the land's exposure to malamancy in the first place.