The Demon from "Tricks and Treats" who manages to reduce the evilly stoic Sister Jude into a panicking, shouting mess.
Leo, who had already had his arm torn off and repeatedly stabbed getting up and tackling Bloody Face.
"Anne Frank" shooting Dr. Arden.
When Sister Mary Eunice possessed by the demon warns Dr. Arden about smacking her again, he does it anyway. And gets psychically flung across the room.
From the same episode Lana's escape from Bloody Face's Torture Cellar.
She smashes a picture frame into Dr. Thredsons face, literally making him have a "bloody" face.
Kit saves Lana from being strangled by Dr. Thredson by knocking him in the head with a fire extinguisher and they leave him Bound and Gagged in a closet. Lana threatens to "bury him" before running off.
Better because all he can do is glare while they run off.
In the same episode, Sister Jude stabbing Santa in the neck.
Jude doing everyone's eardrums a huge favor, by shattering the insipid record that always plays in the common room, also earning Lana's trust and praise in the process.
Lana backing Thredson into a corner with the taped confession, throwing his earlier 'plucky' comment back in his bloody face.
Monsignor Howard throwing Mary Eunice off the stairwell, killing her and ending the devil's reign of terror over Briarcliff.
YMMV: As well as the Angel of Death, kissing Mary Eunice, saying she'll take both of them (Mary and the Devil) ending the Devil's reign on the asylum and ensuring it did not possess anyone else.
Thredson sees a newly-released Lana stepping into a taxi. She sees him heading her way, and gives him the finger while holding up his confession tape. He's absolutely fuming as the taxi drives away.
Mother Superior Claudia sacrifices her career to help Lana get out of Briarcliff and see the asylum itself shut down and destroyed.
Lana finally puts an end to Thredson's reign of terror over her by shooting him in the head and releasing his crimes to the police.