Severus Snape Survived the war. He was turned by a vampire in the boat house to be used as a portioner for the Crossroad Coven. Severus did not comply - instead murdering the entire coven and going out in his own. He is driven from town to town following his hunger. Until he comes upon his singer. The blood of Y/N calls to him so potently he decides to savor it. Keep her. So he can feed on that Devine smell always. His obsession quickly evolves into something more.