Damn, posession. I genuinely didn't think of that. And thinking about it now, it makes way more sense than reincarnation. But that also means Takae unknowingly robbed Marika of a fraction of her life which she'll never get back, and if she continues to stay, she will just steal a little girl's life. Keisuke's going to have to make a decision. Either he keeps Takae bound to Marika, effectively killing a little girl to get his wife back, or help his wife pass on permanently so that Marika can live her own life. At least this time they'll finally be able to say goodbye to each other. I was honestly annoyed that the author kept the monk's explanation about the truth a secret twice, but in retrospect that was a damn genius move with how it was revealed in the end.