I’m not really sure how I managed to miss the thematic similarities between Serenity and Dollhouse until now. The thirteenth episode, Epitaph One, really brought them home: both are about loss of innocence in a universe where power’s in the wrong hands and—more importantly—the idea that a person, even one who has no memory of herself, is still a person. Still the same person she always was, in fact. You can see evidence of this theme as early in Joss’s career as Tabula Rasa and even the Vampire Willow episodes of Buffy (“And I think I’m kinda gay…”).
The other notable theme involves the idea that people can be made better or be given what they need; in the Jossverse, an attempt to do this invariably leads to the creation of creatures that are both more and less than human. The Reavers of Serenity were the result of an attempt to make humans peaceful, to encourage them to accept the control of the powerful few at the center of everything. The Butchers of Epitaph One are nearly identical. While originally intended as an army, rather than as an attempt to make people peaceful, they are still the result of an attempt by the powerful few to recreate human beings in a particular image for their own benefit.