The Indomitable Martial King

In a world where humanity trades otherworldly species as slaves, the great mage Rifenhardt is vilified as a Demon King simply for aiding them. When a party of heroes arrives to vanquish him, Rifenhardt heavily injures them, only to face ultimate defeat at the hands of the Martial King, Tesslon. Drawing upon his remaining strength, Rifenhardt miraculously activates a forbidden time and space regression spell. But upon waking in the past, he discovers an unthinkable twist: he has been reincarnated into the body of his greatest nemesis, Tesslon—the legendary Martial King and the strongest warrior on the continent. Now, armed with the peerless physical might of his former killer and the unrivaled arcane knowledge of a great mage, Rifenhardt embarks on an epic journey to reshape the destiny of the world.