Yu-Gi-Oh! VRAINS - Cyberse World

Cyberse World, often simply referred to as the Cyberse, is a hidden digital world in Yu-Gi-Oh! VRAINS, created and populated by sentient AI known as the Ignis. This world was under attack by the Knights of Hanoi, led by Varis. One of the Ignis, Ai, was able to keep its location hidden, before barely escaping "Cracking Dragon".

The state of Cyberse World is critical and has been reduced to a wasteland by an unknown force led by none other than Lightning and Windy, two traitorous Ignis.

The Cyberse World was created by the Ignis, AI with free will, as a place of their own inside the internet, where no humans could reach it. And it is also the birthplace of the Cyberse Monsters. The Ignis divided the duties of maintaining their world among themselves, each dividing Cyberse into their own territories. In Ai's words, the Ignis would never try harm humanity, and would rather live in their own world.

One day, Ai was fooling around the water domain with "Linkuriboh". Aqua warned Ai not to be playing around, since it was dangerous. Ai didn't mind, but he nearly hurt himself when he fell down a waterfall. Aqua scolded Ai, reminding he should behave like an Ignis. Earth was jealous, and demanded of Ai to stay away from Aqua, as he'd protect the latter. Ai, unlike other Ignis, had a human's instinct. Due to his rebellious behavior, Lightning observed him, believing that his disposition would inspire the other Ignis to evolve.