Buffy the Vampire Slayer
The First: The First, or The First Evil, is the creator of evil itself. The First has no body (incorporeal) and can not physically affect things. It can look like anyone who has ever died. This includes dead humans (Buffy's mother Joyce), vampires (Drusilla, Spike), and even Buffy herself. The First had an army of very very old vampires called Turok-Han and a cult of humans called The Bringers that did things for it because it could not do them itself. The First can not be killed. Its army and cult were destroyed in the final episode of the series and its plans were stopped. The First was the main villain in season 7.