There were many worlds in the dark void that existed outside Aigas.
The sheer degree of variety among them was staggering, but because most living things spent their lives within the boundaries created by the Deities who made their own worlds, it was usually difficult to fathom just how broad and diverse the species and power systems that existed elsewhere in reality were.
Mana as a concept was universal, but different Divine beings wove into something that matched the vision they had for the world they wished to create; this included the supernatural power structure, the species that would thrive on their worlds and the natural characteristics of the world itself.
Other than this, almost nothing was the same, especially when considering that some Deities were stronger than others and had different ways of creating worlds.