Maou to Yuusha ga Jidai Okure ni Narimashita

Igusa, a young man consumed by an obsession with all things villainous, finally achieves his ultimate fantasy when he is reincarnated as the Demon Lord he always admired. However, his grand ambitions are immediately thwarted by a grim reality. The new world he awakens in has been devastated by a catastrophic interstellar war, leaving both magic and swordsmanship in a state of irreversible decline. He possesses the title and power of a supreme overlord, yet the very planet he was destined to conquer is already teetering on the brink of total collapse, rendering his dark aspirations seemingly pointless. Refusing to let his dream die, Igusa seizes an unexpected opportunity when two unlikely figures appear before him: a girl who proclaims herself a Hero and a beast-eared traveler from another world. With the wicked grin of a true antagonist, he wastes no time forcing them into his service. If there is no land left to subjugate on this dying world, he will simply expand his conquest to the stars themselves. Together, this mismatched trio embarks on a bold campaign across the cosmos, transforming a ruined planet's last days into the opening chapter of a universe-spanning dark fantasy driven by one man's relentless pursuit of evil.