Erotic Kill (1973)

In the Madeira Island, the mute Countess Irina Karlstein is the last descendant of the evil Karlstein vampire family. She lives with her also mute servant and seems to be nymphomaniac, seeking for sex most of the time without satisfaction. Irina likes oral sex with men and women to suck off not only semen, but apparently also blood, killing her male and female lovers.