Undercover Agent Becomes Supreme Demon Lord

He infiltrated the demonic sect as a righteous cultivator's spy—just a simple undercover mission. But as he climbed the ranks, mastering forbidden techniques and earning the trust of demonic elders, something unexpected happened: he became too good at being evil. Now the Supreme Demon Lord of the realm, he's trapped in the role of a lifetime with no way out. A tale of accidental ambition where going undercover means going all the way to the top.