Responses

from what I have read in spoilers.. the OG Sellonia is in Grace's body and yes, her father is deeply involved since he is the one that started the ritual of soul swapping.. and the soul swapping required a lot of sacrifice== deaths of people.
OG sellonia does not want to join the expedition due to her not liking to live outside. She wanted the comfort and luxury while still be called a hero/saint after whoever soul is in Sellonia's body.. so after the saving, she can just swap with current Sellonia and reclaim her life..
Please give me some spoiler, From what I gather, it seems Sellonia's father is the root of all this disaster, but what I don't understand is, if that's not Sellonia's soul, then where is the real Sellonia's soul? And if the real Grace is in the basement, then who is the fake Grace? And if Grace has a younger sister, why was her younger sister's and father's face never shown from the beginning of the story? So, couldn't Grace's real family recognize the change in their own child? Or have her father and younger sister also been brainwashed by that fake Grace? Please, someone, give me an answer to my question if you know.