From publisher blurb:
The Lower Planes are home to many foul and dangerous denizens. The demon race is particularly dangerous, given their propensity for destruction and the pleasure they gain from corrupting that which is good and lawful.
Formed from the souls of those evil, chaotic souls that succumbed to the worst excesses of sin, these spirits find a new outlet for their destructive desires as embodiments of pure chaos and evil.
Discover the demons that make up the rank and file of the Abyssal hordes, from the lowly stinky sloth demons to the fierce swamp demons.
Uncover new templates to create spheres-equivalent demons (and inspire to create other outsiders). Open the gates to Infinity and unleash the demons of Sphere’s Bestiary: Demons of the Abyss: Rank and File in the campaign.
For Pathfinder 1st edition and the Spheres of Power/Spheres of Might systems