Emanuelle e Françoise (Le sorelline) (Emanuelle's (1975)

Emanuelle is out to avenge her sister, who committed suicide after escaping from her sadistic lover Carlo. So she chains Carlo up in her basement, drugs him, and forces him to watch her having sex. As Carlo begins to hallucinate all kinds of bloody horrors and cannibalistic doings, he decides he has to break free and kill Emanuelle.