Wizards have divided the ecosystem of this world into four levels: the Sky Ecosystem, the Earth Surface Ecosystem, the Underground Ecosystem, and the Ocean Ecosystem.
All four of these ecosystems either contain or once contained traces of Wizard Civilization, and the ocean is no exception.
The civilization that existed in the Ocean World is called Atlantis, a Wizard Civilization that was contemporaneous with Acadia.
Together with Visnate, the Sky City, and Molun, the Earth Core World, they are collectively known as the Four Great Ancient Wizard Civilizations.
It's said that Atlantis was once a vast supercity built within the ocean, blending magic with urban architecture, extending from underwater all the way to the surface. The city's population exceeded one billion, making its scale absolutely terrifying.
At the time, the entire ocean was essentially under the dominion of Atlantis. The ocean's creatures and various tribes all obeyed its command.
