Heaven got divided into four while the earth was split into nine. Thus, there were the Four Heavens and the Nine Worlds.
The Nine Worlds were the cultivation worlds in the mortal world. The top three worlds among them were the Devil World, the Demon World and the Heaven Immortal World. Next was the Earth Immortal World. The remaining five were the Rain World, the Sword World, the Flame World, the Mountain World and the Tree World. The highest cultivation level a cultivator could achieve in Nine Worlds was the Void Fragmentation Realm. Occasionally, there are cultivators who fail to ascend and become immortals and were known as rogue immortals, rogue demons and rogue devils.
