She is known only as "the Lady." Her identity, her origins, even her rise to power, are shrouded in utter mystery. And make no mistake, that's purely intentional. That she rules increasingly larger portions of the galaxy with an iron grip and a wave of fear is not remotely in question.
Why she wants to wipe out every human is. And why Barbarella is targeted to be the first and most important human to die is the deadliest question of all!