"Anakin, as Skywalker, as a human being, was going to be extremely powerful, but he ended up losing his arms and a leg and became partly a robot. So a lot of his ability to use the Force, a lot of his powers, are curbed at this point, because, as a living form, there's not that much of him left. So his ability to be twice as good as the Emperor disappeared, and now he's maybe 20 percent less than the Emperor. So that isn’t what the Emperor had in mind. He wanted this really super guy, but that got derailed by Obi-Wan. So he finds that, with Luke, he can get a more primo version if he can turn Luke to the Dark Side. You'll see, as this goes on, Luke is faced with the same issues and practically the same scenes that Anakin is faced with. Anakin says yes and Luke says no."