Welp. Judging from the raws, Dowun and the princess seem to have grown more distant. At least, that’s the impression I got. I don’t know why but I’m getting the feeling that Dowun might die in the end or at least not end up with the princess,but that’s just me.
Woah, Dowun's finally done something I can agree with.
I thought he would immediately go to the most powerful princess if he had the opportunity, since power is his only goal.
I'd say there's a bit of a different nuance here. It's not that she's obsessed with him and would do anything to keep him only to herself. It's more that she has had nothing at all her whole life, finally got one thing that is supposed to be for her alone, and this spoiled girl threatens to steal it from her. Think of a cornered, starving animal that finally found food. If something else tries to take that food for itself, the animal will absolutely fight for it.
I wouldn't call this girl yandere. It's more fighting against the girl who has bullied her for years and Dowun just happens to be the object of conflict here.