Gabriel Rosewood

 was the leader of a cult. In 1965, he had encountered the "Highgate Vampire", which was actually a creature called a Corvid. He craved the taste of power he held when he was held in the creature's grip, and by 1972, seven years later, plotted to use his followers as bait to gain the Corvids' power. In 1972, the Corvids attacked and drained the psychic essence from several of Rosewood's followers as they gathered in Highgate Cemetery, and subsequently turned on Rosewood himself. (COMIC: The Highgate Horror)