Okay I’m not 100% but the blonde who proposed IS the one one from a different nation. This prince is one from her nation and scillia HAS to prove allegiance to him. So he’s a new character.
i will add, she doesn't need to prove allegiance to him yet. she is suppose to come and give their father an oath, since he is still the emperor (which is kind of a general noble oath, nothing of the sort this woman mentioned right now). but since the guy is the crown prince, he is suppose to be the next one in line to receive the oath... although as you see, he will likely fuck it up and become their enemy, since he wants way more (and MC will have none of that bullshit).
also, that guy is indeed someone else tho, i was also confused for a while.
they act a bit similar tho, which doesn't help lol. but i think once you see how ML reacts to both of them it will be more clear. ML relationship with this one will likely be way less banteringly and more like "i will kill him first and ponder later".
wait when they say crown prince are they talking about one from a different nation or the blonde one who proposed to scilla?