The Nun's personality is based on Mother Apollonia's extremely cruel and authoritarian behavior. She fits the profile of a rage-filled psychopath. She is shown to be vindictive and cunning, setting up traps like the barbed wire pit on the staircase to make those unfortunate enough to fall in suffer. She appears to take sadistic pleasure in instilling fear in her victims, screaming loudly as she chases them, openly displaying a dead body in the chapel and once she has cornered her target she will take her time mocking them with harrowing whispers before gruesomely murdering them with utmost prejudice.