The Holy Grail of Eris, Vol. 1 (light novel)

Connie is a young noble lady whose only standout quality is her sincerity.Maybe that's why she loses her fiancé and gets framed for a crime allin the span of one night. Just as all hope seems lost, the ghost of aninfamous villainess who was executed years ago possesses her and clears hername. With her incomparable charisma and intelligence, the spirit of ScarletCastiel turns the tables in the blink of an eye. In return, Connie insiststhat she help uncover the truth surrounding her new benefactor'suntimely death and a conspiracy that continues to this very day!