|Although this article is based on canonical information, the actual name of this subject is conjectural.|
The shadow caster manual was an old tome that came along with the mystical shadow casters, which told the origin story of the first slayer, Sineya. It was in the possession of Nikki, who passed it to Robin, who eventually passed it to Buffy Summers.The manual was large and was very old. Its pages were yellowing and tattered. Its nondescript brown leather cover appeared to be just as worn out as its pages.
The text that it contained were written in Sumerian. It was initially translated by Dawn. However, once the shadow casters were completely set, the text magically transformed to english. It warned whoever was assembling the casters that he or she could not just be shown, nor could he or she just watch. The story had to be seen, if one was willing to make the exchange.