"Contractor of Light" is an original science fiction fantasy novel that combines elements of time travel, supernatural combat and hero growth. It is deeply influenced by the Japanese tokusatsu drama "Ultraman" series, but unfolds the story with a new world view and character settings. The novel is narrated in an intertwined first-person and third-person narrative, focusing on the transformation of the protagonist Chen Yu from an ordinary modern person to a warrior of light, and explores themes including protection, loneliness, responsibility and inner darkness.