So...they have a sociopathic bloodline? I kind of like that there is another reason for the prince’s “doll-like” alternate futures. I like that Heronia wasn’t just special, and the prince wasn’t just brilliant. There being a reason outside of the romance aspect makes this more interesting. And it shows how important Bertia is too.
If this is the end, it would be really interesting to read a side story that’s from the parents’ perspective. It sounds like they were struggling to try and give him something to live for.