Mischievous, provocative and unable to take rules seriously, Wei Wuxian hides behind his jokes a total loyalty and a keen sense of justice. He carries burdens alone and reveals them to no one, and his habit of silently sacrificing himself sealed his tragic fate.

Robbed of his orthodox path, he invents demonic cultivation, which manipulates the resentful energy of the dead. With his flute Chenqing he commands corpses and spirits, and he created the Stygian Tiger Seal, an artefact so powerful that every sect wanted it. He is also a gifted inventor of talismans.

Taken in as a child by Jiang Fengmian, head of the Yunmeng Jiang Sect, he grows up as Jiang Cheng's brother. The destruction of his sect by the Wen clan pushes him toward the demonic path during the Sunshot Campaign. His protection of the last Wen survivors makes him an outcast among the sects, until his death. Resurrected, he investigates a series of mysteries with Lan Wangji and uncovers the truth about his past.

Lan Wangji is his soulmate, first a rival annoyed by his antics, then a faithful companion. Jiang Cheng, his adoptive brother, is both his family and his deepest wound. He feels immense tenderness for Jiang Yanli, his sister at heart, and protects Wen Ning, the Ghost General.

In the donghua he is voiced in Chinese by Lu Zhixing. In the drama The Untamed (2019) he is played by Xiao Zhan, who owes his fame to the role. Only the novel fully shows his romance with Lan Wangji.