[Archer can deliver a whole lecture. The more he knows, the more chances to understand how Heavens work.]

Shinki don't remember their past for a reason. They only possess an inherent knowledge about the world they lived in and their skills. Regaining a memory, either from someone that knew them before, or from historical records if they were someone like you, causes a shinki to turn ayakashi. Given that the gods know what their shinki feel it also puts their god at risk.