Sima Yan was a gloomy-faced and ambitious cultivator who served as the vice commander of an army of ten thousand demon soldiers. Operating under Commander Wang Lin, he played a key role in the military affairs surrounding Wang Lin’s rise to command. Known for his calculating demeanor and deep killing intent, Sima Yan’s eventual downfall came as a result of his cruelty, ambition, and defiance against Wang Lin’s authority. (Source: Xian Ni Wiki)