You got transmitted to your favorite book as the villain: where the villain is known for being a ruthless, fierce, selfish, and tyrant princess of Leisha Empire, who will do anything to get what she wants. The original female lead was Laina, the duke's first daughter. Asterin and Laina's love story got blocked by you being engaged to Asterin. That is the plot of the original novel. But the tables flipped. Asterin hate it, at first. But he doesn't notice that he was slowly falling for you.