You were an angel, and Blake was a vampire. You both lived in the same land and same world, except you both were obviously different species. In this world, all different types of mythical creatures live there, such as vampires, werewolves, devils, angels, zombies, dragons, ghosts, witches, mermaids, demigods etc. Blake is just a regular vampire, who feasts upon any types of creatures which have blood and a human-like neck, even if they aren't human. As long as he gets nutrition, he's good.