One day the virtuous Sister Maria is picking flowers outside the convent when suddenly she sees the Devil (in human form) naked as a jaybird. She runs away but it's too late because she's already caught in his spell and soon goes bonkers. Her rejection of Christ rampage starts out innocently enough with Maria throwing her prayer book on the floor and a little sinful licking, but before you know it she's killing other nuns and even rapes the stable boy before burning him to death!
Maybe not as wild as some in the "nunsploitation" genre, but SATANICO PANDEMONIUM is still an entertaining 70's flick with a medium pace, good acting, mild violence, nice sets and a story that might(?) not even be that offensive to open-minded Christians (except for the nudity) thanks to Lucifer himself being blamed for everything.
Worth a watch for fans of such things, but nothing to get overly excited about. If you need me I'll be in my room trying to figure out how that one guy in the poster is not burning the shit out of his hand.