We know Vader wants Luke to join him, but it is evident Luke doesn’t want to. He needs the emporer to help turn Luke to the dark side, then kill the emporer, Vader really doesn’t think there’s any light left in himself. Till the end? Does Luke’s speach about his father before him do the trick? It was only when Luke was getting shocked he betrayed palpy. He thought about it too. That was his chance to kill the emporer. Remove the you were right stuff and remove aniline force ghost, and Vader never goes to the light, might work out well for edits of ep vii and 8.