Well, he needs time to adjust, I don't blame him be chronical ill, you just kinda give up hope of becoming better.
He is probably full of questions and feeling insecure, now.
I am saying that because I am also the grumpy type when I am insecure, lol
Actually, if think back to when Eleonora first met him as a child, it isn't too fathom why he has a strong negative reaction to Ibelina's effect on weakening the curse. He had a back experience with the people that's said to be able to lift the curse, and likely associates Ibelina having some ulterior motives if she's also one that supposedly can lift the curse.
Definitely not the powers of a side character, definitely a protagonist.
@Psychronia: no, it's stated in the earlier chapters of the manhwa that the curse was placed on the empire's imperial family by the king of the neighbouring country when he was executed.
but the current emperor did something to pass the curse from his son to Alejandro since duke Vel Laviti (Alejandro's family) is a relative of the imperial family