I know everyone is obsessed with the love haha but talking about the story, I'm not sure if Kyungjoon's idea would be good (I know what will happen, but still I think about his plan) . He knows that 3 wives have died already and still would push his sister to marry Lee Nok. Dude your family might be quite influental, but you saw already that the Queen is working with ghosts and curses, yet you choose to throw your sister into it? Nah
Help Lee Nok as his royal bestie, not as the brother of his wife... That sound like an either suspicious or very stupid idea.