Shachath (pronounced ʃaħat or shah-_CH_ath) also known as "The Angel of Death" is a recurring character on American Horror Story: Asylum. She is portrayed by Frances Conroy. Her name means "to destroy or ruin".
Not much is known about Shachath at this moment. She only appears when she is called and gives those who call "the kiss of death" when they're ready and is portrayed almost like a "Grim Reaper". Sister Mary Eunice seems to be quite nervous when she encounters her after witnessing the kiss of death being given to a Briarcliff inmate known as Miles (who appears to have summoned her). She has appeared to Grace, Lana Winters, Sister Jude, and Timothy Howard.
Dark Cousin - This is her first appearance. She appears to several main characters, such as Lana Winters, Sister Jude, and Grace. In the end of the episode, she gives Grace the kiss of death after she is shot by Frank in an attempt to protect Kit Walker.
The Coat Hanger - Shachath appears to Timothy Howard in the sanctuary as he is nailed to the cross. Timothy pleads for her to help him, and she replies "I'm here".
The Name Game - Shachath does not end Timothy's suffering, but believes he must cast away the Devil that possesses Sr. Mary Eunice. She later appears when Mary Eunice dies, saying she's taking both her and the Devil.
Continuum - When Briarcliff is put under the control of the state of Massachusetts and turned into a refuge for surplus inmates, Judy Martin is confronted by a domineering, unnamed new arrival who seems to bear the physical appearance of Shachath, though her voice is raspier due to cigarettes. When she attempts to usurp Judy's role of authority amongst Briarcliff's populace and sexually harasses her, Judy attacks "Shachath", only to find that the Angel was part of an elaborate hallucination she has been suffering from over the past two and a half years.
Madness Ends - Shachath appears to Jude, who is willing to accept the Kiss of Death this time around.