The tack this seems to be taking is that the Purported Saintess doesn't know at all how her power actually works (yet,) and that the Prophet who disappeared does know, engineered things to ensure she'd be causing havoc in the royal family.
if so, I'm a bit disappointed. A plot where it's a hoax initiated by the purported Saintess, rather than having her be duped as well, lets fewer of the other characters off the hook for their actions.