The Villainess and the Demon Knight (Manga) Vol. 5

Cecilia, daughter of a marquis, eagerly awaits her engagement ceremony with her fiance, Lucas. But a dark cloud is about to rain on their joyous occasion. Every hundred years, an ancient dragon threatens the kingdom, and a hero is chosen to slay it. Usually, the hero defeats the dragon but dies in the process--and this time, it's Lucas who has been chosen to fight the dragon. Now Cecilia's heart is filled with grief, just when she should be most blissfully in love.