Yeo Euiyeon, once a respected figure within his martial sect, vanished without a trace after betraying his order—murdering his own master and fellow disciples in cold blood. Do Haegun, one of the sect's most promising young warriors, was raised like a son by Master Euiyeon. But after being suddenly abandoned as a child, Haegun grew up with a deep scar—feeling discarded, betrayed, and driven by resentment. Years later, under orders to track down the fugitive Euiyeon, Haegun sets out on a mission fueled by a twisted blend of loyalty and vengeance. But on his journey, he crosses paths with a mysterious man—someone who looks uncannily like his former master, yet behaves in completely different, disarming ways. Is this truly Euiyeon reborn? Or a stranger caught in the shadow of another man's sins? In a world of blades and betrayal, what will Haegun do when the line between past and present begins to blur?