Cassandra was the younger daughter and middle child of Achelous Alexander and his wife, Nike. She had an older sister, Sophitia, and a younger brother, Lucius, with whom she ran the family bakery in Athens. In "Soul Edge", she was mentioned as having witnessed her sister's unconscious body being carried by female ninja Taki after the two successfully destroyed the cursed sword Soul Edge. Taki shared to her the information about a Soul Edge fragment that was lodged near her sister's heart, which Taki was unable to remove because it would kill her. Cassandra resolved never to tell anyone about this, even Sophitia herself. Three years later, she heard her sister had gone to another journey to destroy Soul Edge in "Soulcalibur". Unlike her sister, whose skills originated from her weapons and the god Hephaestus, Cassandra was not as humble and could not hear him, relying instead on her own strength.