| The subject of this article is non-canonical.|
While created as part of licensed material, it has not been confirmed as part of the "real" Buffyverse continuity.
Born in 1510, Cassia was 15 when her father unknowingly invited in two vampires. By the time she heard her family's cries, they and two servants had been killed. Cassia fought the vampires, realizing that she had an inhuman strength and easily killed them. A week later when a female Watcher arrived, informing her that she was the Slayer and needed to be trained. This proved to be difficult, as Cassia resented her Watcher and the Council greatly, blaming them, their monsters, and their destiny for the death of her family.
She began sneaking out to hunt without informing her Watcher and in 1527, she fought and lost to the 1300 year old vampire Syrus the Gladiator. Once sired, she continued to slay vampires as well as feast on humans. The Watchers Council never knew about her turning, considering her dead. She continued to train after death, learning the fighting technique Pencak Silat in Malaysia,. She then massacred not only her instructors but the entire village after.
In 1960 she terrorized a small town in Nebraska and earned the name "Drifter Killer." She met Angel in a roadhouse nearby and attacked him. Incredibly strong and fast, she had a stake to Angel's chest when she was shot by the local sheriff, saving Angel.
She has assumed various names through the ages, such as Callia in late 1800, when she met Spike at a saloon; Catia in 1950, Poland; and Celina in 2000, Sunnydale, when she challenged and attempted to convince Buffy Summers to join her as a vampire. She was eventually defeated and staked by Buffy.