Tensei Reijou, Kekkon no Susume - Akujo ga Gimai no Kawari ni Totsuidanara

I lost my fiance to my sister-in-law, but I'm going to be happy with a different kind of frontier count! Rafina is called the "Poison Flower of King's Landing" and is rumored to be a vicious man-crazy girl. Her sister-in-law has stolen her fiancé, and she is forced to marry a "monster frontier count!"　Rafina's husband is a kind man, despite his hideous appearance. Rafina gradually forgives him and..?!