Hey guys,

i really need help with this. I tried everything to find this manhwa from what I remember of the plot but i haven't been able to find it.

FL is engaged to someone and she belongs to a special group/kind of people that has strict rules for marriage. She has to marry on a specific date and if she doesn't both her and her fiancé die. The wedding is held at a mansion of a duke who is quite cold and serious. Suddenly a girl appears who is special and the fiancé has to guard her until the temple people arrive. The girl tries to bring a wedge between them and then disappears. Fiancé goes after her and both get stuck in a small house in a snow storm. Wedding day comes and FL is on the verge of dying. Theres blood on her wedding dress. Right before she dies the Duke steps in and marries her to save her life. Fiancé marries that other girl because she also belongs to the special group of people.