Ask the Devil to Let Me Go

The male protagonist accidentally entered a different world and was summoned to the Demon King's Palace to endure the torture of the crazy Demon King. After death, he was resurrected by the magic of rebirth and became immortal. He upgraded and spawned monsters to go to the human world. The human world is divided into nine regions. The Demon King's Dark City is one of the nine regions. The human world is divided into Dark City, Light City, Fire City and Sea Palace. Forest City, Rock and Earth City, Weapons City, Wind City, Thunder City, in the end the hero and the devil lived a life without shame.