The Indomitable Martial King

In a world where humans buy and sell otherworldly species as slaves, the mage Rifenhardt is branded the Demon King for helping them. When a party of heroes comes to defeat him, Rifenhardt badly injures them, but faces death at the hands of Tesslon, the Martial King and the strongest man on the continent. As a last resort, Rifenhardt casts a spell that sends him back in time. He awakens in Tesslon’s body, becoming the very hero who once tried to kill him. Now a great mage in the body of the physically strongest man, Rifenhardt sets out to change the world.