Aegmerism

The ancient legends speak of one who bears no one name, the Ancient Carnians called him Aegmer, the Coenians knew him as Aézéoth. But, almost to everyone, he always appeared as The Man with the porcelain mask, the best name to describe him by.

Nobody would dare offer anything to the god, except the mad cultists seeking the apocalypse, but still, everyone knew, that this mysterious god was the most powerful of them all, unmatched as compared to the rest. They may as well have been small rats in comparison to this dark eldrich entity.

The Man with the porcelain mask would often appear to you in your time of worst need, and offer you help - of course always in exchange for something. And, he would always give you exactly what you bargained for - no more, no less.

A young boy's soul and the greatest Empire in existence
Once, the son of a great Caeron was approached by the Man, for instance, and seeking glory and honour his house, he bargained away his soul in exchange for eternal glory and recognition. He was, however, tricked. Knowing the stories of old, he expected The Man to take his soul when he died, but the cruel trickster took it in that very moment. The young boy would, in his long life, create the greatest Empire the world had seen in a thousand years, however, he could not appriciate it even for a moment - for with his soul, he lost all feeling, emphaty, and happiness. The Empire, which he built on tyranny and suffering, shattered immediatly upon his death, and his house, which he wanted to raise like it never was before, was doomed to die out, hated and despised by all. Nobody knows why The Man does this, perhaps he or her, for its identity is never quite clear, just toys with us.