Fiends are fiends

Demons and devils have always have more similarities than differences. Their hierarchies, their goals, their appearances, etc. Some of them are chaotic, others lawful, but in the end fiends are fiends. AD&D DMG Appendix D used the same random generation tables for demons, devils and daemons. Why equivocate? To coincide with my condensing of the Lower Planes into one plane of arbitrary size, I am likewise condensing the various differences between fiends.

Alignment factions primer

I do not think the two-axis alignment system really makes much sense, but unfortunately for me it is baked into the design of the game. Even if PCs do not need to select alignments, the monsters and cosmology (including my homebrew) are still informed by alignment. So I am going to reframe the alignments of chaos, evil, good and law into allegiances loosely based on "Essences" from Mage: The Ascension or "Urges" from Nine Worlds or the factions from Age of Sigmar.

The order/chaos conflict

The worlds of 13th Age are locked in a fairly typical conflict for mythology: orderly civilization versus chaotic nature. [Insert fumanor references]

Order is informed by Ancient Egypt's Ma'at and Michael Moorcock's Cosmic Balance (rather than stultifying Order). It recognizes that chaos may be constructive (e.g. forest fires making way for new growth).

Chaos, then, represents mostly or only the destructive aspects.

Alignment, moral ambiguity and grimdark fantasy

5th edition downplays the influence of alignment on the rules, but it still informs the canon cosmology and my simplified cosmology. Instead of arguing the meaning of alignment, I prefer a practical approach in the form of allegiances. Inspired by Mage: The Ascension and Requiem Chevalier Vampire, my cosmology is the backdrop for a conflict between four opposing forces with dramatically different yet sympathetic world views.