Mu Qingkong, the "Sword Immortal" in the mortal world, is the only disciple of Master Fanyi, a reclusive monk. He has experienced ups and downs in the rivers and lakes, and has no complaints or sorrows, but he has a unique understanding of "the benevolence of a chivalrous person". He and Ruan Xingyun, the left envoy of the Demon Sect, have different paths of good and evil, but they have the same mind. Can a single choice and the reincarnation of cause and effect save them from this world? Regardless of their identity, they can only recognize the four words "the benevolent heart of a chivalrous person"...