DanXurin, the Lord of Black Pleasures, was not worshipped by many. Even before the Great Purge to rid the land of dark and evil cults, the cult of DanXurin was far underground, for DanXurin was nothing less than a god of pain and torture.
The practices of the Children of the Lord of Black Pleasures were enough to disgust hardened soldiers, used to the carnage of the battlefield. Rumors of people tortured to death over a period of at least a year as sacrifices to DanXurin were sometimes whispered between travellers, but those who said too much about the Black Children tended to go missing. Sometimes they turned up sometime later, horribly mangled corpses. Sometimes they never turned up at all.
The leaders of the Great Purge were thorough, but a group so firmly wedged into the cracks of society as the Children of the Lord of Black Pleasures could not be completely exterminated. At least one cell of the cult survived, led by an utterly demented butcher of a man named Ashur. He had once been the chief inquisitor of the infamous Gannos the Bloody, but had been dismissed because the unholy glee he took in his work alarmed even his master.
While Ashur did not particularly care about the fates of his fellow cultists, he meant to punish those who had presumed to stop the Lord of Black Pleasures’ work. More than that, he wished to expand the cult’s sphere of influence even more. He meant to summon his god to this world, giving him a form of flesh and bone.
There were barriers to such a thing, and it would take years to do it properly. It mattered little to Ashur; he could wait. He started preparing a suitable vessel for the Lord of Black Pleasures.
That vessel was Ashur’s own son, eldest of a pair of twins. From almost the time the boy could grasp a knife, the cult leader had him right next to him, committing atrocities on unfortunate captives in his dark god’s name before he could even walk. He grew up amidst unspeakable acts and gore, and the screams of the cults victims lulled him to sleep.
While raising his eldest son to be the vessel of the dark god, Ashur was also preparing his youngest son to be the sacrifice to breach the final barrier and summon forth the god. The younger twin was systematically tortured almost from the day he was born, although never enough to be fatal. By the time the boys were four years old, this torture was carried out amost entirely by his brother.
Ashur was not ready to perform the summoning ritual until the twins were fifteen. He called the cult together for a ceremony unlike any ever seen: the summoning of a god. The cult was eager to see the ritual completed, and worked themselves into a frenzy as the elder brother gouged out his twin’s eyes to start the ritual.
Something went wrong. Maybe Ashur hadn’t got the steps quite right, or maybe DanXurin never really existed to be summoned. Maybe it was the fact that the younger twin had come to enjoy being tortured, or maybe the elder had ascended to a different plane of existence by that point, rendering it impossible for the god to inhabit his body.
What ever it was, the ritual had an effect, just not one anybody was expecting. Both twins had somehow become demons. The elder became Oni, the torment demon. The younger became Engel, the agony demon. When the cultists realized what had happened, they rioted. Engel threw himself into their midst in order to satisfy his masochistic needs, while Oni amused himself by torturing other cultists to death, starting with Ashur. Some cultists fled the ceremony, but many stayed. Sometime later, a fire started, gutting the Palace of Black Pleasures and killing any cultists still left alive inside.
In the end, only Oni and Engel were left, and they went their separate ways, at Oni’s insistence (after all, torturing a masochist was no fun at all).
But the Children of the Lord of Black Pleasures are still around; those who escaped the final ceremony spread out and many founded new cells. Other cells might have survived the Great Purge, lying in hiding. It’s been decades, maybe centuries since the cult was almost wiped out, but cults have a way of growing.
Perhaps the cult is becoming bold again, and making a much-feared name for itself.
Perhaps surviving members, or their descendants, of Ashur’s cell think the ritual to summon the Lord of Black Pleasures was simply incomplete, and wish to find Oni and Engel to finish it.
Perhaps another cell is trying the same ritual, except they are not using their own children; they might have kidnapped locals to be the vessel of DanXurin or the sacrifice to breach the final barrier.
Perhaps somewhere, a cult leader succeeded where Ashur failed, and an avatar of DanXurin, the Lord of Black Pleasures, now walks the earth.