A post-apocalyptic dark fantasy. Thousands of years after genocidal wars wiped out civilization and awakened dark forces from another dimension, the remnants of mankind struggle to survive in a savage world dominated by evil necromancers.
I'm channeling pulp sword and sorcery specially Conan as REH wrote him, from a Lovecraftian point of view - there is no good god, the supernatural are really alien entities from beyond space, magic is a grisly, twisted, obsessive affair that leads to madness, and barbarism triumphs over civilization.
So my influences and inspirations are: Reh's Hyborian Age, Almuric, Moorcock's Hawkmoon, bdsm fashion, Heavy Metal, the Coldfire series of CS Friedman, the Claymore anime series, vampires and werewolves, the fantasy horror stories of Clark Ashton Smith and the like.
Who are the pcs? The pcs should be barbarians. They're the last clean-living people left, and their ignorance makes them interesting to play - there's so much in the world for them to discover. Civilization in this world is corrupt and dehumanizing, leading to loss of freedom and dignity.
The civilized parts of the world are broken up into despotic city-states, separated by wide gulfs of barrens - lands where nothing but the weirdly mutated life of Necrosis can grow - and by the barbarian territories. The barbarians are alternately a pest and a source of slaves for the decadent, pallid, hedonistic, nobles of the cities. These city-states are slave societies, where a small class of nobles lord it over a much larger population of unfree subjects. Even the commoners, those who aren't slaves, are perpetually in debt to the nobles simply for the privilege of living inside city walls.
Unlike a typical fantasy world, however, the agrarian population is quite small. The cities grow much of their own food in hydroponic farms. There are however homesteads and ranches that do grow crops and livestock outside the cities.
Elements of the setting - barbarian swordsmen, slavery, despotic city-states, decadent civilization, dark foul and grisly magic, demonic entities from other dimensions, yoma-like doppelganger demons. What is the long-term goal of the characters? To survive and keep their humanity.