Plagues, wars, famines, and the undead are the Four Horsemen of the Apocalypse in the Church of Light's propaganda. Their arrival would bring apocalyptic disaster.
The last one, the Undead Empire staunchly denies. To them, their Undead Calamity is just a form of warfare, a controllable one, not a calamity in the true sense. Yet, if anyone dares to defy them, they surely would hasten the arrival of their doomsday.
Whether the Undead Empire admits it or not doesn't matter. What matters is that everyone believes it. Among the disasters listed alongside the Undead Calamity – plagues, wars, famines – all of them terrible in their own right, the plague is considered the worst.
There was once a region heavily afflicted by plague. Two-thirds of its tens of millions of inhabitants died. All systems of government collapsed in this region; only the isolated villages managed to survive.
