Mary was Guy Cecil's sister who was killed years prior to the events of the story when Duke Fabre invaded the House of Gardios with Kimlascan soldiers. The maids and women of the house, including Mary, rushed to save the young Guy, but they were slaughtered before him. Guy lost consciousness during the event and awoke buried in the corpses of Mary and the women, triggering his severe gynophobia. A replica of Mary is later created by Van Grants, which toys with Guy's mind and makes him unable to attack her. The replica is sacrificed, along with many other replicas, at the Tower of Rem when Luke fon Fabre and Asch use the power of their hyperresonance to dispel the planet's miasma.