Julian Karswell was not a scientist - mad or otherwise. He was the leader of a cult , who, having transcribed an ancient work, was able to summon demons and cast black magic spells. He lived with his mom at Lufford Hall, Warwickshire. Don't look for it, it's been magicked away since.
Dr. Julian Karswell is the main human antagonist on the 1957 film Night of the Demon. He is a mad scientist and was portrayed by Niall MacGinnis.
Any villain inspired by the legendary Alistair Crowly deserves respect. Based on a short-story by the classic ghost story writer M. R. James, the villain of this movie is the mysterious Dr. Julian Karswell, a magician and leader of a cult. When a psychologist famous for debunking the paranormal threatens to expose crimes perpetrated by the cult, Dr. Karswell has no choice but to put a curse on him, which invokes a fire demon to kill the victim. With supernatural powers and demons at his disposal, Niall MacGinnis plays a formidable villain who transcends his Gothic type thanks to a dose of dry humor and an unsettling politeness, making him look like an anicent.