In flashbacks of when a star fell while Shion and his father was camping, in the reflection of his eye there's an apparition like Yin's possessed specter, was this Izanagi or was Shion born as Izanagi?
EDIT: From an answer, it's clear the apparition was not Izanagi. However, I did type the description wrong, as I'm asking about the apparition Shion saw after the star struck him and his father.