sentences:  Kuon reveals that she was Rei's twin sister that died in the womb, and that her soul was absorbed by Rei after her death, and when she was dragged into purgatory their souls split back into two, which allowed Kuon to work in the background to be able to get Rei enough power to defeat the demons.Kuon then fights Rei, and Rei is forced to kill the sister she just met, absorbing her soul, giving her her full soul back and making her more powerful as she was now whole again.The alcea also causes everyone Rei met to gain the memories of the previous timelines as well, though this includes the demons twins.