This was an englightening chapter. I used to wonder what the prince's deal is, whether he's just deadly bored and is manipulating people for amusement. Or perhaps the king has ordered the princes to manipulate the children of the noble families to weaken and control them, that is, the princes would need to prove they can rule over the nobles with no remorse. That would be essential for the prince selected for inheritance.
But now looking at the prince's face and reading his lines, the riddle was easily answered: he's a psychopath, nothing more, nothing less.