Status Updates From The Swan's Daughter

At this point, I can tell it's not going to do it for me.

Beautiful writing and lyrical worldbuilding.
But, I don't feel anything for the characters nor their story.

Arris could be interesting but he annoys me. His hormones seem to control him a lot.
And Demelza is a bit fade at the moment.

I’m really enjoying this, except there’s one plot point that has me completely befuddled. Why is everyone trying to murder Prince Arris? Can’t the power only be earned by 1) winning the heart of an heir and 2) either marrying them and sharing the power or cutting out their heart to steal the power? What good is murdering him immediately? Am I missing something or is this a major plot hole??