Cassandra is not a normal human being but an artificially cultured individual who was reproduced from Maria Lancelot's genes. She possesses a Stigmata body that exists with 80% Stigma tissue, but because her body couldn't withstand the power of the Stigma, she was put into suspended animation until the problem was solved.
Cassandra was briefly awakened in 2049, where she met and bonded with her brother Ryuuichi and niece Kazuha. During her time living with Ryuuichi, his wife Orie became pregnant with Cassandra's nephew, Kazuya. Orie would eventually experience complications due to Kazuya's stigma body, forcing Gengo to have Kazuya transferred to Cassandra in order to save him and his mother. Cassandra would become a surrogate and give birth to Kazuya, bonding with him as though he were her son. Cassandra would raise and take care of her nephew Kazuya until he was two years old. Cassandra was then placed back into stasis until she was reawakened by Su-Na Lee during the 12th Nova Clash along with two of her sisters to join the battle.
Cassandra has very long blonde hair, gold coloured eyes, and a very buxom figure. Before the experiments, she wore a simple dark blue sleeveless top, a long white skirt, and kept her hair loose. When she awakens from her long slumber, her hair is pulled back by a black barrette, and she has inhuman yellow eyes, with orange pupils. She also has a green Stigmata protruding from her collarbone. Cassandra also dons an elegant and low-cut white and lavender dress, with cross patterns around the hem of her raiment.
Cassandra is usually a very quiet person, much like her sisters Teslad and Lucy Renault, and rarely talks or changes her expression. Despite this, she is a loving woman who adores children, and despises mothers who don't love their children (i.e. Kazuya's mother). She's very affectionate and protective of her nephew Kazuya, and glares ill-intently at anyone who she deems a threat to him. Aside from him, she rarely converses with anyone, save for her father and her sisters.