Hell
The Princes of Hell created and molded their dominion into one unified and efficient system. Now their ilk decided they were products of a bygone age, useless in their goals for conquest over Earth. The demon uprising spread the Princes thin and most abandoned their post, leaving the world for dead. Beelzebub, the last remaining Prince, seeks help from damned souls to become his Champions. Warriors, he hopes, that are strong enough to bring his brothers back to their thrones.
Devout followers of the Princes split up in 7 churches. They are often cruel women and men of the cloth, seeking to punish the wicked or those who dare oppose their Lords.
The middle ground between Hell and Heaven. Humans live their days unaware of the existence of either realm. No strife ever seeps into the mortal plane but rural folk would have you think otherwise. Abyssal influence and other supernatural occurrences are usually common in more isolated communities as they happen to inhabit areas close to gates of Hell.
Immortals looking for quiet lives settle on Earth, hiding their identities or their existence altogether.
While holy, Angels are often aloof as they're creatures of light blessed by God.