Orichalcos God

The Great Leviathan is a gigantic serpent creature who is behind all the events in Season 4 of Yu-Gi-Oh, Waking the Dragons. He employed the Orichalcos stones to take over the world. It was these stones that made Dartz of Atlantis turn evil and use the Orichalcos stones and cards to seek out victims to steal souls from to feed to the Leviathan. The souls of Grerimo, Maximillion Pegasus, Yugi, Weevil Underwood, Rex Raptor, Alister, Valon, Joey Wheeler, Mai Valentine, Rafael, and Seto Kaiba were among the many fed to the Great Leviathan. The final soul was that of Dartz himself, after he lost a duel to Yami. Yami battled the Great Leviathan, and eventually used his power to destroy him, causing him to shrink down to nothing. Dartz was released from his control, and the souls of all his victims were returned during the battle.