Plane of Air
Skybound Lands
Hey, the upside here is if you do end up falling over the edge, the gravity makes you fall onto the underside... That or you wouldn't have to worry dying from it. Hitting the floor kills you, not the drop itself.
The Plane of Air is one of the elemental pillars of the Cosmic Hourglass. Home to a world where there's no up and down, of gushing winds and storms galore. Described as the endless skies of the multiverse, it is a place where having a grounding is crucial to one's survival.
Skybound Lands
As told beforehand, the Plane of Air does not exist on any solid ground, rather it exists in an empty space with no up and down. Anything that ends up here finds itself floating around, carried around by gushes of winds. One has no weight here, and as such can technically swim wherever they want.
For as calm as the realm can't be, it's also home to thundering storms and cutting hurricanes, able to tear asunder any Airship traversing them. Sometimes they can be spotted from miles away, other times they manifest out of nowhere. As such, one unexpected weather change is capable of destroying an entire fleet in one fell swoop.
Islands & Structures
Although ground is scarce, some solid ground does exist floating around the area. Everything from isolated chunks of rock and dirt to structures built by the inhabitants. To ensure that all of it sticks together, many also possess an Orbiton core, whether it be natural or artificial.
As such, what little land there is either is densely populated, or merely legends in folktales. What little resources exists are expensive to get and land is fought over on a daily basis.
Inhabitants & Ecosystem
Inhabitants
Inhabitants of the Plane of Air tend to call the place Auralius, as few actually live in the sky lands themselves. Due to the scarcity of resources, populations are small, either living as nomads or securing what little ground they have.
Many who live here are not native to the realm though, as races of all planes traverse this world. The few that do have a permanent home here are Djinns and Air Elementals amongst others.
What sets their society apart though is their advances in Airship technology. Due to the existence of Orbiton metals, the law of gravity is in control of their kind, allowing for otherworldly devices. From nation-sized stations floating mid-air to Airships where people live and die on board.
Ecosystem
Most of the plane's ecosystem has adapted to a life without solid ground, either possessing wings for flight or some sort of levitation. Either they utilise what little land there is to its fullest extent, or form relationships with larger creatures to reproduce.
As a result, plantlife is scarce, either found on the few bits of land existing in the Plane of Air or as a parasite feeding off hosts. Hence most life have developed a carnivorous diet or more abstract forms of substance such as lightning.
Realm of Thunder & Lightning
Auralius
The plane makes me think a bit of Larry Niven's book, "The Integral Trees". and more sky pirates. https://en.wikipedia.org/wiki/The_Integral_Trees.