As far as production values go, one of the very best nunsploitation films
The Nun and the Devil (AKA Sisters of Satan, AKA The Nuns of Saint Archangel)
Italian nunsploitation directed by Domenico Paolella. In a 16th century convent near Naples the Mother Superior is dying. There are three candidates to take over the role. One of them is not content to wait for the process of voting and selection, deciding to take matters into her own hands by means of poisoning and blackmail. She achieves her goal and is elected the new Mother Superior. However, the games she has played to get there and the people she has upset along the way result in anonymous letters to the Cardinal detailing her crimes including her intimate relationships with other nuns. The Cardinal orders his deputy, Carafa, to conduct an inquisition into the affairs of the convent, and especially the behaviour of the new Mother Superior.
This is well above the average nunsploitation flick, with a damn good story centred around the corruption and hypocrisy of the Catholic Church (on the one hand clamping down on the moral failings at the convent, whilst on the other accepting 'questionable' donations and brokering land deals with powerful local figures). The production values are terrific. It was filmed at a real convent with a large cast, the costumes are lavish (especially those of the Catholic hierarchy), and the performances are all very, very good. The gorgeous cinematography of Giuseppe Ruzzolini also deserves a mention. English actress Anne Haywood plays the scheming would-be Mother Superior, Italian exploitation favourite Martine Brochard and Muriel Catalá play her lovers, Claudio Gora is the Cardinal, and astonishingly exceeding expectations with the best performance of the lot, exploitation 'himbo' Luc Merenda puts in a terrific turn as the Cardinal's deputy and chief inquisitor, Vicar Carafa. Ticking the nunsploitation boxes there's a lot of skin on show, some very softcore nun/nun sex, and quite a hard-hitting torture sequence towards the end as various nuns are forced to admit their sins and transgressions. Not just an enjoyable nunsploitation, but a very good film in its own right. 8/10