This part of Suzerain's cosmos has no physical existence per se, no land, no water, no trees and grass and rock and dirt. It is a mere chaos of energy, constantly in motion, a far flung part of the spirit world that has no correspondence to any reality we know and it is shielded from mortal time by the Veil.
Yet beings live within the Maelstrom, accustomed to its ways and attuned to its energy, able to tap that power for various effects. Some of those beings are powerful enough and wise enough that they have learned the true nature of the Maelstrom and can reshape its very substance, at least in a limited area. They have created cities and valleys as real as any in our world. Such mighty spirits are the gods, and their lands are collectively the immortal realms.