Something that is used in quite a few vampire books, movies and shows is the whole vampire and vampire’s servant relationship. You have the Underworld movies where the lycans are the daytime protectors and slaves to the vampires. Then in Bram Stoker’s Dracula you’ve got the insane Renfield who worships Dracula and is completely devoted to the vampire. And in more stories than I can count you have the obsessed fans that beg the big bad vampire endlessly for immortality. It goes on and on – but there are a few different kinds of vampire/servant relationships.
– In some stories a vampire will drink from a little blood from human and then let the human drink a small amount of blood from them (but not enough to turn into a vampire) and the result is a telepathic bond between vampire and human. The two have become closer on a deeper and magical level. This is similar to the human servants in the Anita Blake novels, or in True Blood.
– There are then the vampire stories where the vampire uses their hypnotic powers to force a human into serving them. In some stories this can destroy the human’s mind if not done correctly. You see this kind of hypnotic control a lot in The Vampire Diaries; it’s also been used in Anne Rice’s novels, the House of Night series, and about a hundred other books and movies.
– The vampire can seduce the human into becoming their slave. Just the idea of becoming a vampire’s personal sex toy will make many humans willing to obey any order from their vampire lover. I’ve seen this relationship in a lot of vampire romance novels, of course.
– Sometimes, usually when the vampire is of noble blood, the human simply loves and respects the vampire so much that they will do anything simply out of friendship and admiration. This is another one we’ve seen in Anne Rice’s novels, usually with Marius.
– Then there are circumstances where a vampire will just use fear as a way to gain obedience. This has been used in damn near every single vampire book or film out there.