The Sisibans are the predominant species of the planet Sisibi, who live divided among the five kingdoms.
Sisibans are similar to humans in appearance, but are radically variant in their innate biology.
Almost all inhabitants of Sisibi are born into a separate kingdom. Due to the magical influence of each kingdom's Beast, the Sisiban cultures that reside in each kingdom have developed specific mutations over thousands of generations:
- Earth Sisibans are stronger than other Sisibans, and have a special connection to the planet.
- Fire Sisibans grow large calcified scales on their skin, protecting them from the extreme volcanic heat.
- Water Sisibans have mutated gills on their necks, allowing them to swim freely outside of their bubble-domed cities.
- Metal Sisibans are all born without eyes, and are given mechanical eyes at birth.
- Air Sisibans are unnaturally tall and limber, standing a head or two above even the tallest non-Air Sisiban.
Sisibans move between kingdoms freely, depending on the laws and regulations of their target kingdom. Some Sisibans are unable to live in certain kingdoms without the help of powerful magic:
- Earth Sisibans cannot live in the Fire Kingdom, due to the intense heat.
- Fire Sisibans cannot live in the Water Kingdom, because of the high humidity.
- Water Sisibans cannot live in the Metal Kingdom, because the mountain cold would freeze them.
- Metal Sisibans cannot live in the Air Kingdom, as the Air Kingdom looks down upon artifice.
- Air Sisibans cannot live in the Earth Kingdom - why would they ever want to?
Some Sisibans, whether due to choice or having been exiled, live outside of any kingdom. After a few generations, children born to exiled parents will come out with no mutations.
All Sisibans are herbivores, unable to digest meat on any level.
Sisibans eat a diet composed of "energy blocks" that are dug out from the crust of the planet. These blocks contain enough energy to keep any Sisiban going for a full day. No other food is necessary - pure energy is the most efficient way to keep a body going.