Emanuelle e Francoise: Le Sorelline (Cover "C")

This is one of the more bizarre entries in the Emanuelle series, playing more like a sex-themed giallo. Emanuelle (Lindt) is out to avenge her sister (Gori), who committed suicide after escaping from her sadistic lover Carlo (Eastman). So she chains him up in her basement, drugs him, and forces him to watch her having sex. Carlo starts hallucinating all kinds of bloody horrors and cannibalistic doings, so he decides he has to break free and kill Emanuelle.