This is completely average so far. It's a "The villainess wasn't actually evil and the ones who rejected her will come to suffer" story. No redeeming characteristics in the crown prince, step-sister and -mother, or in that merchant. There is one "good" character, who saw how absolutely fuccking perfect and without flaw and beautiful and kind and perfect the "villainess" actually was. And he has now sworn revenge against those who have hurt this perfect and beautiful and kind and perfect girl. Yada yada yada. You can find this exact story slightly differently dozens of times on this website.