The No-Eyed God is the god of Insomnia, Undeath, Cannibalism, Torture, and Willful Ignorance. He was a sorcerer-king, and has ruled for eons. So much so that the chiefliest of his servants are buried in their own tombs, and his own corporeal body given way to lichdom.
He is the wellspring from which the undead flow, and was creator of each in their own perverse design.
From willing corporeal followers he found new ways to give them strength and let them cheat the reaper’s scythe by convincing them blood was wine and the flesh of their brothers food to sustain themselves. He had to tell no lies to do so, they were able to trick themselves into the consumptive cycle. The thirst and the hunger is all they know now.
And from victims he found new ways to torture them beyond the grave, snatching bits of their soul-stuff and letting them be consumed by their own extremes. He replayed their pains to them over and over before they could cross to the other side. They chose to stay back themselves, untethered from the physical world. The pain and hate is all they know now.
The dead won’t rest if he has his way.
For Undeath is Insomnia, and Insomnia is Undeath. They are the same. You sample the living dead when you do not sleep well, and the reason is the dead envy your ability to dream. They kill you not because you need to die, but because they’re so jealous they must kill.
His cults subversively spread his teachings by masquerading sinisterly as other faiths. “The Church of the Feast”, “The Blind Faith”, “The Child Looking Away”, “The Order of Eternal Vitality”. All lies, and at their deepest circle of trust they carve the meat from the still screaming victims and lap the blood from the table, thankful for the splinters in their tongues and the pain and rot it will produce. They prey on the needful, the hurting, and the ignorant. Their pilgrimage leads to open graves, and horrifying falsehoods they embrace like lovers.
His lesser priests willingly undergo ritual torture, so much so they become akin to medical waste cenobites- idiot sadists with scabs and clots of someone they once cared about between their teeth. Some remove their eyelids to prevent sleep. Greater priests have no need of senses, craving to be closer to their god, needles are driven into their eyes, their mouths sewn shut, and hot lead poured into their ears. Still they preach his unholy truths: there is another, Darker world just on the other side. You only have to look the right way.
They wear his holy symbol openly: a skull without eye sockets, fangs instead of teeth, often made of razors or broken glass to cut the user.
Some volunteer for living sainthood, undergoing repeated sleep-fasts, until they are placed in a coma, or repeatedly lobotomized, sometimes by their own hand. Often afterwards they are slowly, slowly eaten by their friends and fellows.
Many times these deeper worship practices create ghouls, the lowliest of undead troops, carrying their disease as a “blessing” to the world. Sometimes though, a much more foul undead mentor will spread its taint in a growing subversive cult, a vampire, a wight, or some fouler thing not yet seen. Like locusts they consume, and like infection they spread.
Behind all this, is a deeper obsession: to carry out not just his will of a stygian world of undying monsters, but to speed the coming of the will of The Dark to the world, to see this world and all others subsumed into the cold infinite, and bring it insidiously closer to the No-Thing.