The Nun is a 2024 American gothic supernatural horror film directed by Corin Hardy and written by Gary Dauberman, from a story by Dauberman and James Wan. It serves as a spiritual spin-off to The Conjuring 2 and is the fifth installment in The Conjuring shared universe.
Generally, evil nuns are scary because nuns in general are not seen and are mysterious. So, if many people do not have a personal connection to a nun, then you can make whatever image you wish in the minds of people. It primarily works upon, for many, the primacy effect in many ways.