The Devil's Wedding Night (1973)

Plot

Set in the 1800s, scholar Karl Schiller believes he has discovered the legendary Nibelungen ring at Castle Dracula, a site of immense power. His twin brother, Franz, a risk-taker, teases Karl about his fear of vampires but accepts an Egyptian amulet meant for protection. Arriving at the castle first, Franz encounters a mysterious countess who lures him to dinner. When Karl arrives, he learns it's the Night of the Virgin Moon, a rare event that draws five virgins from the village, who mysteriously vanish. Will Karl be able to save his brother and the young women from a sinister fate?