Abaddon is a wasteland of infinite and apocalyptic proportions that is home to the daemons. It is dominated by the citadels of the Four Horsemen, but includes vast stretches of uninhabited wastelands, and smaller holdings of minor warlords and vassals. Abaddon holds the headwaters of the river Styx, which flows from here out through the Maelstrom, often touching Hell and the Abyss to eventually pool below Pharasma's spire.
Most of Abaddon is unnaturally quiet, like a land depopulated by war or plague, and is covered in a cold, black mist. The air feels heavy and rotten, and what little light exists is provided by a strange, sun-like object in permanent eclipse.
Citadels of The Four
The Throne of Flies
- The citadel of Pestilence, ruled by Apollyon. Plaguemere is a vast swamp of disease and torment surrounding the citadel, which is a huge afflicted corpse, perhaps that of a dead god or protean lord.
The Drowning Court
- The citadel of Death, ruled by Charon. A rickety collection of artificial islands chained together above a whirlpool, it as at the heart of Charon's domain, the fiendish river, Styx.
The Cinder Furnace
- The citadel of Destruction, ruled by Szuriel. Surrounded by plains scattered with massive knife-like projections of obsidian, swathes of ash, smoke, and bone, and blackened lesser daemonic fortresses, Cinder Furnace is carved into the heart and walls of an immense dead volcano.
The Weeping Tower
- The citadel of Wasting, ruled by Trelmarixian the Black. This minaret of mucus and pus pulses, fluctuates, and trembles with internal lights and screams. Here the hideous experiments on the nature of the soul and its torture and destruction are carried out.
Daemons are the most populous of Abaddon's inhabitants, born of mortal souls who died a most terrible and violent death. They feed upon souls and are ruled by the Four Horsemen, who epitomize the four main ways of mass killing: war, famine, plague, and death from old age. There are rumors that a fifth horseman exists, an archdaemon of incredible power who rules the Four, but others claim that he is dead, and the Four now ritually devour him.