The Imperial System: Architect of an Empire

When Kael Asterion dies on Earth, he awakens as the Tenth Prince of the most powerful human empire in another world—a realm where eleven royal heirs compete for the throne, ancient races despise humanity for centuries of slavery, and kings secretly bargain with demons for power. Hated by nobles, abandoned by his mother, and believed to be powerless, Kael disappears at the age of seven. Ten years later, he returns with the Imperial System—the mysterious power that no one else possesses—and learns a terrifying secret: In twenty-five years, the Demon Realm will invade, and the world will end. While his brothers fight over a crown, Kael begins building something far greater than a kingdom. From a forgotten estate, he will raise an army, transform an empire through innovation, forge alliances with races that once called humans their greatest enemy, and expose the rulers who have already sold their souls to the darkness. In a world where everyone seeks to become Emperor... Kael intends to become the ruler who saves civilization itself. To save the world... he must first unite it — Description from novelcodex.org