The Staff Edit
The Staff seem to corrupt everyone that get in possession of it. It turns Missi into a Vampire in the Night and she turns back human after briefly loosing it in the Episode "The Silent"
Duke does not turn human after loosing it in The Night and stays in his Vampire Form, even still being able to use some of his powers during the following episodes.
The Staff displays various other Powers through the Series. One being able to turn on torches and candles in a room, and emitting a velvet like fabric that can be used to catch and trap objects and persons.