Cross-Dressing Villainess Cecilia Sylvie, Vol. 5 (manga)

Although Cecilia and the boys rescued the heroine, the next death flag is fast approaching. After returning to Vleugel Academy, Cecilia must conquer the Mordred route-a difficult feat while dressing as a boy. Plus, the mystery of Killer-s identity and hiding her own from her dearest fiance, Prince Oscar remain top priority...