Daemon World: Brainstorming ideas for a post-apocalyptic, PF Daemon-ruled world

[Marcarius5555]

Daemons (https://pathfinderwiki.com/wiki/Daemon) are, to me, a really evocative villain class. They're the evil that even other inhabitants of the Lower Planes find revolting. They're also, per my subjective assessment, not over-used as villains in published materials. I was pondering a setting where the daemons are basically in charge of a prime material world, and what that would look like.

Some questions for brainstorming

-How did the daemons take over? Was it a war? Did they subvert another religion and launch a crusade?
-What unique races, if any, exist in this world? I had some inspiration from here (https://www.drivethrurpg.com/product/123802/Obsidian-Apocalypse-PFRPG).
-What kinds of non-daemonic kingdoms still survive in a marginal way -- are they well-concealed tribes, armored arcologies, etc?
-What are the daemonic plans for this world now that they have largely taken it over (perhaps this also raises the question of their original aims, which, admittedly, might have changed)?
-What do the daemonic polities look like -- are there four main realms, each devoted to one of the Horsemen, or some other arrangement?
-What kinds of unique/distinctive mechanical subsystems might operate in such a world.
-What kinds of environmental changes might have followed the daemonic incursion?

That's all I have for now -- looking forward to seeing any responses!

[Erik the Bard]

Some answers that your questions generated:
1. I'm thinking neutral evil wouldn't just conquer the world like chaotic evil, but subvert and subsume it. The daemons slowly took over the good-aligned churches and replaced those in power with daemon cultists. These high-ranking individuals then started a war between the churches, citing ancient religious feuds, depleting their resources. THEN the Horsemen of the Apocalypse were summoned to the mortal realm, and conquered the weakened nations.
3. Some random ideas: drow and dwarf strongholds deep in the underdark still resisting the daemonic conquest of the surface; elven kingdoms retreating to the Feywild and then squabbling amongst themselves; at least one nation protected by Asmodeus; and a Star Wars type "Rebellion" that resists the new rulers.
4. Stealing from WoW, the daemons want to consume the soul of the world.
5. The Four Kingdoms engage in civil wars and deadly politics now that the conquest is over. The Kingdom of Plaguemere is ruled by Apollyon, Prince of Flies. Plague daemons and diseased goatmen are at his eternal command. His forces seek to spread sickness among the ranks of the other kingdoms to take them over. If Apollyon gorges himself on the world soul, he will set himself up as Emperor of the Mortal Plane.

Just some thoughts. Hope you liked.

[quinron]

I think you'll be best served by really doubling down on the "what is their plan now/what was their goal in doing this" question. Remember that daemons' ultimate goal is the cessation of all mortal life; they're not devils who will be content to rule with an iron fist, they're doing this as a step toward annihilation. Figuring out their next step will inform their strategy and tactics for accomplishing it, which will inform how they've impacted the world, which will inform how mortals have responded.

[Bohandas]

-What are the daemonic plans for this world now that they have largely taken it over

I'm gonna say torture. That's the whole plan. Just torture. Forever.

EDIT:
Possibily it's a little like The Matrix. Only instead of using the Matrix they keep humanity in place with screws and nails.

[Aliess]

How about it simply being a new staging area for their "real" war against some other foe? Native enclaves are fine, and provide some entertainment so long as they don't get powerful enough to threaten anything important.
Or it's a trap! Controlling the prime material plane gives them control of where should go, or risks making it so that no more should will ever be born, or something. This will irritate enough other planar beings so they'll have to intervene and the demons can go for their real target while everybody is distracted.