Let’s be honest: the demon nun, Valak, is the best part of the movie. She’s terrifying in that “I’m going to invade your dreams” kind of way. But in the real Enfield case, there was no nun. At all. Nada. The real spirit, if there was one, was just a grumpy old man who complained about his coat and his chair.
Why the nun? Well, Lorraine Warren, the real-life psychic, said she had a vision of a “malevolent, hooded figure” during the investigation. The filmmakers turned that into Valak. It’s a great creative choice, but it’s pure fiction. So if you’re scared of nuns in the dark, blame the screenwriters, not the ghosts.