Interesting plot twist, so that justifies why the sea monsters attacked Julian and not Diana.
Also I'm kinda conflicted, the King seems to be a good ruler for his people, even if he has a villain aura.
I want to believe that him leaving Diana alone would be the right choice, but what if whatever being that blessed her overtake her emotions or something? Or maybe the mystic creatures that grant powers intentionally put this vision on the prophetess so the conflict would arise (wouldn't happen if they left Julian and Diana alone), dunno maybe these creatures are bored.