People really went mad with this story line LMAO.
I'm cool with it actually.
So now that Kyoukai bring Rei out of darkness, the only thing that they need to do is to have Rei join the HSU and we can finally move on from there. Always knew that Shiki sacrificed herself to Rei so that Rei could live a good life and Kyoukai uses Talk no Jutsu to snap Rei into reality. And chapter 669 btw.