From publisher blurb:
A dark star fell from the sky bringing with it the end of all things! The sanctity of the world known as Abaddon was shattered when a global apocalyptic event of a meteor impacting the planet causing a destructive ecological and eldritch change. Now there is no day or night, just never ending Apocalypse. An undead world ruled by fear and horror. Undead nightmares prowl the darkest forest with malevolent ghouls, grim demonic fiends and horrific vampires prey on a fearful populace. The world is dominated by the monstrously powerful immortal evils that reigns supreme over this world. And with all this the mysterious force known as Nightwall. Evil dominates the world to be challenged by noble heroes fighting to take back a world that should belong to them. Are you willing to take up the fight?
Inside this sourcebook you will find the four most powerful dangers in the Obsidian Apocalypse setting:
New Monsters: Boneshard Golem, Crion, Dark Cherub, Eye Thief, Hargila, Necromantically Infused Creature (Charnel House Hound), Neuread, Shadow Ripper, Skin of Evil, Souleater, and The Voiceless
Environment & Hazards Dangers: Air, Necromantic, Arcane Slime, Arcanebleed Mold, Coffin Mold, Crimson Fog, Desertbloom, Falling Trees, Glass Storm, Hellish Fog, Necromantic Fog, Necromantic Slime, Nightwall, Ochre Slime, Scarlet Mold, Sludge Chamber, Spectral Slime, Starfallen Slime, Swollen Corpse and Terror Stones
New Diseases: Arcane Pestilence, Cursed Fire, Demonic Plague, Mana Rot, Necromancia, Shadow Sickness, Slimy Doom - Crimson and Whispering Doom