Demoniac

A disturbed priest, who witness an occult ritual, thinks the people are possessed and start a private inquisition to exorcise the demons by torturing them to death.

 

Demoniac originally went out as Ripper of Notre Dame. Director Jess Franco, discreetly avoiding his given name of Jesus Franco, plays the title role. He's fun to watch in a disgusting sort of way. Lots of slashing, lots of nudity, little sense-but you probably guessed that when you read the title. The film also exists in a hard-core pornographic version titled Exorcism and Black Masses, available at off-brand video rental shops.