Brides of Blood (1968)

Brides of Blood is a horror sci-fi movie set on a tropical island that is plagued by mutations, monsters, and human sacrifice. A group of people, including a scientist and his wife, a honeymooning couple, and a missionary, find themselves trapped and fighting for their lives as they uncover the dark secrets of the island. As they struggle to survive, they must navigate through superstition, murder, and supernatural horrors.