The "lesson" this series tries to teach is outright terrible. You're not allowed to cheat death/reincarnate/possess/whatever because "that's just the way it works, mmkay"? Oh, you actually did cheat death? Well it's not a miracle that should be embraced because "you only get one shot at life, mmkay"?
The series LITERALLY presents the characters with a miracle, and then characters come around and say it's not a miracle because it's not allowed due to "nature not working like that" and other such contrived bullshit. Literally NO PERSON IN REAL LIFE would ever think along these lines. The novelist character's idea of the ending would be more interesting. It's like the series' only point is to DESTROY hope irl by further reinforcing that magical things don't exist and thus you'll never experience a miracle of any kind whatsoever.
This series had so much potential for an ending on either side of the happy/sad spectrum, but it went for a forced bittersweet ending that relied on people not looking at the situation how real people would. If ANYONE in our world had this opportunity they would grasp onto it and never let go, and they most likely wouldn't give a damn about whoever got "possessed". So angry I wasted time on this. Thought it was going to have a nice and sweet ending when they talked about getting remarried when she grows up, but nooooo, this is current-decade writing so we have to have contrived bittersweet/downer endings. Oi.