Once feared as the Murim's biggest threat, Yeom Se-Ak, also known as the Slaughterer Demon Monarch, was captured by Han Ho, the Sword God, and trapped in Mount Hua for a century, biding his time for revenge. The world eventually forgot about him, but fate brought him face-to-face with his nemesis once again, reigniting his desire for vengeance. When the demon unknowingly reveals Han Ho's name, it sets the stage for a new twist in Yeom Se-Ak's vendetta.