Yu☆Gi☆Oh! Duel Monsters

Synopsis

Yami Yugi is being absorbed by the Great Leviathan, as he still has darkness inside. With the light of his friendship, however, he is able to channel enough strength to lock away the Great Leviathan, ending the catastrophes plaguing the world. Dartz is freed from the Orichalcos and returns home with Kris and Ironheart. Yugi and Yami leave Atlantis, while the others flee the island as it collapses. Everyone whose soul was captured awakens. Mai leaves Valon with her Cyber Harpie and promises to face Joey in the future. Yugi and Yami wash up on shore and are visited by Dark Magician Girl and the Legendary Knights, who tell them that their world is safe. Then, the Legendary Knights return to the Duel Monsters Spirit World, promising to return if such a great darkness ever threatens the world again. Afterwards, the others find Yugi and rescue him from the island. Before Yugi departs from the island, he agrees that Yami that needs to find out the secrets of his past, and promises Yami that he will not be doing it alone.

(Source: Wikipedia)