Thinking about it more there better not be some cr** about how if a Saintess is married she doesn't lose her purity if she sleeps with her husband. If that were the case than the current Prince if he marries the saintess and that is how he restores her powers, then wouldn't that mean that he was the one who rap'ed her? That also seems weird since it would have been pre-marital relations. If the ML is the one who rap'ed her then no, just no to this story.
Read Cursed Princess Club, it's finished and fantastic.