One Piece: Starting By Playing Gilgamesh Template.

Kazama Haruto transmigrated into the world of One Piece four thousand years in the past, beginning by assuming the role of the King of Heroes, Gilgamesh! With a single hand, he established the Uruk Empire, leaving behind countless mysterious legends. Yet at the very peak of his power, he fell into a slumber that lasted four thousand years due to a system upgrade. Four thousand years later, as the great powers of the seas gradually begin to uncover scattered traces of the Uruk Empire… Kazama Haruto, who had slept for four millennia, steps out from the Golden Capital. With an invincible bearing, he once again displays the majesty of the King of Heroes upon the seas! And Gilgamesh—the King of Heroes—is merely the beginning… The Five Races wage war against the heavens, the Black Dragon enslaves all living beings, and the Hollow realm constantly gazes upon the human world of the seas… As one long-buried secret after another is unearthed— The entire ocean… descends into complete chaos! — Description from novelcodex.org