I mean ig they meant during early chap the prince(aka current king) gave off huge secret yandere vibes cuz we saw he had some good feeling toward the purple eye duke while kinda off a lil gloomy when he saw the duke(his childhood friend? I forgot) w the long hair dude
FROM WHAT I REMEMBERED, THR EMPEROR JUST LOOKS SUS BUT NO, HE DOESN'T HAVE ANY ILL INTENTIONS TOWARDS THE BOY. ANYWAYS, IF I'M WRONG F ME