Sister Mary Eunice

"Is that redemption I see?"

- Sr. Mary Eunice to Pepper.

 Sister Mary Eunice  (real name Mary Eunice McKee) is a nun serving at Briarcliff Asylum under Sister Jude and a victim of satanic possession.

She is a main character in American Horror Story portrayed by Lily Rabe.

Freak Show
Sister Mary Eunice is seen sitting behind her desk filing paperwork for Pepper. She converses with Pepper's sister to find out the reason why she is being admitted. She tells Sister Eunice that Pepper sliced off her baby's ears and drowned it. Later Sister Eunice makes Pepper an assistant in the library to reorganize magazines when she believes that Pepper has shown humility for her actions when she cries after being freed from her straitjacket (although Pepper was framed for the murder by her sister and brother-in-law).

Asylum
Sr. Mary Eunice greets the visiting Lana Winters and warns her about Pepper's violent nature. She escorts Lana to the administrator's office, where she interrupts Sr. Jude in the act of punishing Shelley and is severely chastised about her failure to knock. She forgets her lesson within minutes, as she bursts in again to announce the arrival of "the bad person" to Briarcliff Manor.

After dark Dr. Arden sends her into the woods to feed some mysterious creatures, she meets Lana, who blackmails her into allowing her into the asylum. After Spivey tosses his feces at her, she confesses to Sr. Jude her part in allowing Lana entry. Sr. Jude berates her stupidity and Sr. Mary Eunice bends over her desk, begging for punishment. Sr. Jude is shocked into pity and smacks her ass before dismissing her from the office.

Upon Jed's death after a lengthy exorcism she becomes the new host for the demon that possessed him. After which, Sr. Mary Eunice seems a new woman, now rather sly and manipulative. She taunts Sr. Jude with a newspaper from 1949 about the little girl Sr. Jude injured in a drunk-driving accident, propositions Dr. Arden, and kills an inmate before feeding her corpse to Arden's creatures. During the showing of The Sign of the Cross, she gleefully awaits the scene in which the Christians are fed to the lions.

As the head of the Asylum Eunice begins her unorthodox rule over the asylum, delighting in having free reign over the establishment. It's not to late after this inauguration that the Demon inside Mary finds it's self confronted by a Holy Host. An inmate suffering from schizophrenia is at the end of his rope and, through some gruesome off-screen antics, summons the entity known as Shachath. In the inmates room this Angel of Death gives him the kiss of death, but before departing Shachath notices that Eunice is watching her. The fact that the nun could lay her eyes on such an entity is an immediate telling sign that she is no mere mortal. The two exchange words with the possessed Sister looking very nervous and frustrated with the host's presence in the asylum. Shachath makes it clear that she can see through the demon's disguise and can see that the real Mary is begging for death and an end to her torment, at this remark the real Sister Mary Eunice breaks free of the demon's control and begs the Angel to release her, but she is quickly silenced by the impatient demon. Shachath promises they will meet again and leaves.

Monsignor, now equipped with a revelation given to him by Shachath, finds himself being attended to by Mary Eunice after he was crucified by Leigh. In a desperate attempt to exorcise the sister, the monsignor lunges at Eunice and places the his rosary on her forehead and begins to recite a prayer. Mary Eunice brushes him off sending him flying back to the bed on which he was laying with his arms stretched out and body held in place by some unseen power. She tempts and teases him as she mounts him and eventually rapes him. Keep in mind that this does not only take something valuable from the Monsignor, but also from human Mary Eunice. She taunts him over his virginity and his body's clear interest in her despite his minds rejection of the despicable act taking place. Mary notices Dr. Arden witnessing from the doorway.

After being raped, the Monsignor Timothy Howard consults with Sister Jude, who's sanity is clearly slipping after Mary ordered she be administered electroshock therapy, in a moment of clarity on her part she tells him to kill her.

Sister Mary Eunice later visits Dr. Arden, who is bringing food to the Raspers, and she suggests lobotomizing Judy, to which Dr. Arden flatly declines. Now despondent over being mocked by the aliens and losing the purity of Sister Mary, he executes the Raspers before attempting, and failing, to kill himself, then begging for Sister Mary to give him some form of mercy. Disappointed at Arden's loss of dignity and desperation, Sister Mary leaves him in the forest.

Again Timothy is confronted by Sister Mary Eunice in the midst of his prayer. She offers her body to him again, he rejects it, she exploits his inner ambitions by hinting to him her grand scale plan involving the Vatican and him as pope, again he rejects the idea. She then taunts him over his obvious desire to kill her and toys with the many ways he could go about taking her life, even revealing that he could use his rosary like he did on Shelly, demonstrating again her ability to know all secrets hidden in her victims mind.

Sister Mary Eunice finishes by reminding the Monsignor that he is weak and after what she did to him she owns him, body and soul. To this he rebuts that she, in fact, does not own him and that he will cast her out. He reminds the demon that he can still sense the true Mary Eunice and will free her. Enraged the demon corners Timothy on the stairway, grips him by his shoulders and promises to not only omit the Monsignor from it's plans but to devour the very last morsel of soul that is left of Mary. At this, the real Mary breaks free and cries to the Monsignor that she is tired and, in effect, can not keep fighting for control over her body, she wants to let go. Timothy tells her to then let him go, she does, and swiftly and without hesitation he grabs Sister Mary Eunice and tosses her over the landing of the staircase, and she falls to her death.

Shachath appears before Sister Mary Eunice as she lays dying. Eunice asks the Angel to take her, Shachath replies "I will take both of you", ending the demon's rein over the sanitarium. Her body is later cremated by Dr. Arden. Still lost in his obsession of her and now completely void of hope or reason to continue living, Arden lays atop her body as is pulled into the furnace where he burns alive along with her corpse.