She is portrayed by Alice Krige, whom also portrayedMorgana le Fay in Disney's The Sorcerer's Apprentice and the Borg Queen in the Star Trek universe.
Christabella is the manipulative high priestess of the Brethren and almost all of the residents of Silent Hill were her followers. She stresses the importance of maintaining purity by purging sin (aka sacrificing people she deemed as sin incarnate) to please her cult's god. The sacrifices were carried out in a secret chamber in the Grand Hotel, containing a painting of Christabella's possible ancestor being burnt as a witch. Dark Alessa mentions that "they have met many times" at the chamber, indicating that Christabella has killed countless innocent individuals in the past.
Before she and her religious group were trapped in the Fog World, Christabella also worked as the headmistress at Midwich Elementary School. There, she tries to indoctrinate most of the students into adhering to the doctrines of the Brethren.
After Christabella's sister gave birth to a daughter out of wedlock, Christabella had the child condemned as a witch. Alessa was bullied and abused by her peers daily, while the members of the cult and her aunt not only allowed it, but encouraged it. After Alessa was molested in the school bathroom by a janitor to escape from the bullying at the age of nine, Christabella convinced Dahlia that she needed to be "purified", calling her "filth" and saying her innocence must be restored. Christabella then had Alessa laid over a bed of burning coals to be burned alive as a witch. When one of the chains holding Alessa in place had broken, Christabella and her followers fled from their secret church. All of the members of the cult, including Christabella, were then pulled into the Otherworld after Alessa split her soul and started taking revenge. Rose Da Silva meets Christabella after she and Cybil Bennett flee to the local church to hide from the coming Darkness. Christabella becomes agitated when Cybil fires a shot in the church to stop the cult members from attacking Rose, declaring that the church is a "sanctuary" and casting an ugly look at Cybil and Rose. She then questions the two women on how they came to be in Silent Hill, and agrees to lead them to the localhospital, where she says a demon lies in wait. When Christabella discovers that Rose's adoptive daughter, Sharon, is identical to Alessa, she has her followers attempt to kidnap Rose and Cybil. Rose escapes, but Christabella orders her men to beat Cybil as she lays on the ground bleeding.
Christabella then goes to the apartment of her now mad sister, Dahlia, at the store called "Nathan Drugs" in Silent Hill where she finds Sharon and kidnaps her.
At the church, Christabella has Cybil burned alive as a witch, and attempts to do the same to Sharon when Rose arrives. Christabella stabs Rose with a dagger, causing Alessa's dark essence to spill out of her and to overtake the church. Christabella and her followers were in horror that Alessa and Dark Alessa are inside the church and Alessa and Dark begin their revenge on them. Alessa then rise into the church with mounds of rusted barbed wire, which Alessa then uses to rape and sodomize Christabella. The barbed wire exits Christabella's body through her back, chest, and mouth; eventually tearing her in half. As Christabella dies, Dark Alessa dances in her blood.