Monster (Larry Stylinson AU Demon/Vampire!Harry Angel!Louis)

Harry Styles. Sounds familiar? 1/5 of the british/irish boy band One Direction?
But Harry Styles keeps secrets. One, he's gay. Two, he's in love with his band member Louis Tomlinson. Three, he's dating his band member Louis Tomlinson. But that's not all.
Harry has a huge secret about who he is. After long time of touring, singing, dating and hiding, he decides to tell Louis who he is.
But Louis was never good at those things since he had been almost killed by a creature at the age of seventeen. So, he does what every sensible human being would do: he runs.
Harry can't let him go, though. Because Louis is something special, has special blood. A lot of creatures want him, want to claim him as theirs.
Louis has to find a way and get along with his monster.