Masters of the Force (Part Three): What does Vader become if he'd survived?
Part One: https://www.youtube.com/my_videos?o=U
Part Two: https://www.youtube.com/watch?v=vkbp8EqPIko
Recaps, containing spoilers, are below:
Part One: During the events of Return of the Jedi, and after the Ewoks agree to help the Rebellion, Luke and Leia have a conversation (as usual) about how Vader is his father and that’s he on Endor looking for him... Luke then says he’s going to go and face him, but Leia convinces Luke not to go. And, not only does Luke not go, but he doesn’t tell Leia that she is his sister...
The Rebels down on Endor still manage to blow up the shield generator... and the Death Star in space above (along with Palaptine) is destroyed as well. However, during the battle Luke separates from his friends to confront Vader. When Vader sees the Death Star destroyed he realizes he’s free of his Master’s hold and hence no longer sees the need to take Luke on as an apprentice...
This is when Vader is bombarded with voices and images from his past that begin to pull him back to the light... but before he can return, Luke is forced to defend himself against Vader and plunges his saber through Vader’s stomach. Before anything else can be done or said between them, Inferno Squad shows up and chases off Luke and promises Vader that he and the Empire will live on.
Part Two: The story moves ahead thirty years, and we get a reunion between Luke and Han/Leia on Coruscant and learn that some tragedy has apparently kept Luke away from them (and everything else) for some time. We also learn Luke has never told Leia that she is his sister and that, apparently, Ben Solo is not Force sensitive. In this reunion we also learn the Senate is worried about the Jedi and would like there to be oversight of them. Luke tells Leia that will never happen, and that he cannot stay and has other matters to attend to.
Next, a mysterious Sith (apparently under the command of Darth Vader) seeks out the hiding spot of the legendary Doctor Aphra and demands she give to her the Holocron of Darth Plagueis. The mysterious Sith than dominates the mind of Aphra and learns she doesn’t have the holocron and has never had it... but that she did once take something else from a secret vault that belonged to Palpatine... which turns out to be a rather ordinary looking stone that, for some reason, zaps the Sith when she touches it.
The mysterious Sith lets Aphra live and takes the stone back to Vader... where Vader then uses the stone to see what he described as “possibilities”. After seeing this, Vader declares it is time for the Empire to make their return...