City of Portals
Races: Aasimarr (10%), Goblins (20%), Gensai (5%), Humans (30%), Tieflings (10%), Shifters (5%), Forged (10%), Other (10%), Dabus (???)
Background: The Eberron version of Sigil is a Dhaakani city pulled into the Astral Plane to escape the Daelkr Wars. The populous has long since largely died out, interbred with demons, or simply moved back to Eberron after the end of the conflict. Instead, the city has become a haven for outcasts from the various planes and those who wish to explore reality. The city in the Astral has hundreds of portals leading to Eberron's outer plane.
Slowly, over the centuries, the populous managed to recover from the cataclysmic transformation and started living in Sigil full time. Their magicians managed to create portals to most of the dimensions with contact being established with Elves as well as the Dragonic peoples. Also, some foolish Sigil members started exploring the Planes full time with some coming back with half-breed children loyal to their parent races or driven quite insane.
At least some of the citizens are actually from ancient Galifar that were rescued by the citizen's planewalkers after being taken in captivity from their homeland thanks to Manifest Zone monsters pulling them through. Others are citizens of other worlds on Eberron's Prime Material Plane with some refugees from worlds destroyed by the Daelkyr.
The city has managed to prosper despite being one of the most strange in the world and its rather intense isolation from the rest of the universe. There are even other towns that exist as established by the Sigilians in other parts of the Astral Plane.
Culture: The city, due to its promixity to the Outer Planes, is dominated by a host of philosophical movements called Factions. All of them have specific roles in the city, both official and unofficial, that generally exist to give each other Hell. Compared to Primes, most citizens of Sigil seem slightly (or completely) deranged in their monomania devotion to philosophy. Don't try and convince them that their ideas aren't new or that no one cares outside of the city, they'll hate you forever.
The average citizen of Sigil is intensely urbane, though the majority of the citizenry lives in poverty and is rather resentful of this state. They have their own rather peculiar slang that seems reminescent of Sharn Thieves' Cant. They are haughty and arrogant to the majority of "Primes" that they treat as just shy of dirt.
Notable Citizenry: Not long after arriving in the Astral, Sigil was taken over by a mysterious Outsider known as the Lady of Pain (TN Female Outsider ???). The Lady of Pain appears to wield power equivalent to a Solar Deva, Pit Fiend, or even Rajah according to some rumors. She has absolute authority over how the portals function and has created a barrier that prevents any non-mortal blooded Outsider from entering the city. The only exceptions are those merged with mortals or those of minor power. A few have managed to "sneak" in but they're forced to operate covertly, so it's quite likely she merely rejects power that flaunts itself.
The Lady of Pain is served by the remains of the Hobgoblins of the city called Dabus (Male/Female LN Hobgoblin Outsiders Sorcerer 4), whom are apparently now all transformed into wizards that cannot communicate through anything but symbology due to their immense lifespans and exposure to the Astral Plane's energies. Those that have not become Dabus have since turned into undead or left the city.