World with Twin Fates
Tarrosque, the Center City
The legend of the center city of the underworld is one of common knowledge to the nobles of the underworld. The common people know little of why the feudal system is in place. What is known is the center city is no longer just a place built around a ever-dying insane beast. Multiple immortal creatures lie in the center city chained by war. The technology levels come from advances garnered through studying these chained gods.
At least that is what they say.