Genshin Impact: King of the Underworld

A transmigrator arrives in Teyvat, but his coming changes the world. His brutal rule brings down Celestia’s divine punishment, and his mighty empire is wiped out in an instant. Yet his soul becomes connected to the underworld of Runeterra, and he becomes its king. The enemies who died at his hands and the former subjects of his empire all become an army of undead, waiting in the underworld for his return. Having already died once, he is no longer subject to erosion. After falling again in the war against Celestia, he waits for a thousand years before awakening once more.