Introducing the Multitude. Homebrew overarching Campaign Setting

[Saint Caleth]

Scientists and Philosophers alike say that there are many worlds, each of which is slightly different from all others. Over the countless eons, some of these worlds have risen to prominence as names out of legend, from the intrigues of the Old World to the splendor of Vashaal to the empire of the Darravi.

I have had a single sprawling, overarching campaign setting for essentially as long as I have been playing TTRPGs, but it has always existed only as scattered notes and campaigns. Now I would like to get as much of it down on paper for people to see and hopefully like as possible but I honestly don't know where to start.

Help me out by taking a look through some of the worlds of the multitude described below and telling me what you most want to see written up so that I can get a starting point in this whole mess. If no one has a strong opinion I will probably just start with the city of Ashalar, but tell me what looks most interesting.

Ashalar:

The first great city of mankind, Ashalar was once the home of the god Marduk in ages past before a great catastrophe forced the inhabitants to split thier city off as a demiplane to survive the end of the world. By doing so, they ensured the survival of the Great Library where all knowledg3 has been catalogued for millenia and ensured their city would live on as the crossroads of the planes.

Tarayacaradath:

Once the home of the mysterious Nashraqim at the dawn of history, Tarayacaradath was the first world to have gods as well as the first world to be destroyed by the internacine warfare of the gods.

The Old World:

The first great seat of human civilization, The Old World once contained the city of Ashalar and the heroic history of mankind's first victories against the Dragon God and later the Dragonborn Emperors. All that was nearly wiped away when the Old World ravaged and destroyed by the dark god Azheer.

Canvarr:

It was the people of Canvarr who first invented firearms in their struggle for freedom from the tyrannical Conjuror Kings and then exported that technology along with their culture to the rest of the Multitude.

The Darravi:

Halfbreeds of human criminals and the monstrous natives of the plane they were exiled to, the Darravi rose to destroy the arrogant civilization which cast away their human forefathers and went on to create a masive empire which contended in cold war for thosands of years with the other empires of the multitude which rose and fell alongside it. Now the Darravi have been conquored and cowed by an even more ruthless foe but they shall rise up again as thy always have throuout history.

Vashaal:

The breaking of Vashaal remains the most potent reminder of the terrible price that reckless magic can exact. Once the most splended of worlds, the factionalism and strife between the great houses spiraled out of control untill it lead to the sundering of the entire plane and gave the multitude its most enduring image of destruction.

The Dyties:

Once enslaved with the threat of the guns of the Canvarrans, the Dyties vowed never to serve any other race and adapted the twchnology of their conquerors before setting off on their own wave of conquest. Now the Dytie empire groans under the weight of its rapid growth and brutal subjegation of conquered peoples. Although a dytie emperor sill wears the Blood Crown how much longer can the empire survive?

The Chapterhouse and The Order:

The Chapterhouse has always stood at the center of the planes. No one knows who built the city sized buildih which spans the demiplane. The Order which inhabits it is far newer however, made up of immortal heroes each reincarnated upontheir death. With no hint as to the purpose of their second life, they have joined together to create a purpose； encouraged to that end by the Walkers, mysterious men and women who appear and vanish at will amd whose nature bewilders even the gods.

There are some locstions to consider to start with. I will be developing fluff, crunch and other sourcebook type things at an irregular pace wherever I start. Maybe I will evenh throw in some adventures or collect everything into a more polished source when the time comes depending on how I feel.

Enjoy, and please help me out by telling me what intrigues you most.