You should put an NTR tag on this. It might not be technically accurate, but you just made it so 10 guys are going to be fking his girl. I don't understand how he is not more possessive of what is his.
It feels horribly short-sighted of the witches to cut off the bond that made Reiko powerful in the first place. Surely they should postpone the ceremony instead of riding it, to let her grow in power rather than force her to halt her growth before its peak.