The Duke is one of the only well written characters in this manhwa. He’s shrouded in mystery but at the same time dropping hints of what his goals are and his personality. He (and Heinley) know what they are doing. The Duke is planning to depose Navier but it isn’t anything personal against her. It seems as though he likes/respects/admire Navier, and that is why he always feels guilty for what he is doing against her. He has his own agenda, and unfortunately Navier is in the way. I like that he is setting Rashta up for failure, but I also hate that it is at the expense of Navier.