Vader was ordered by the Emperor to make sure that the Death Star is operational, by the time the rebel fleet arrives.
He can’t leave. He must obay his master.
He might send some troups though, if he has any at his disposal mind you, since the legions are stationed on the Endor moon, waiting for the rebels.
Plus the Emperor knows that Skywalker will come to Vader, and he tells this to Vader exactly when he needs to. When Vader’s job is done on the Death Star, and has some time to kill before the rebels arrive.
So logically, Vader is not going anywhere.I see what you are saying, especially in relation to Vader’s character as presented in ROTJ. However it is clear in ESB that Vader is undermining the Emperor and plans to betray him. (The Emperor informs Vader of there new enemy, who Vader has already been searching for.) I would personally do away with most of the “I must obey my master” type dialogue, I see Vader as a slave to the dark side more than to the Emperor himself. If Luke, Vader and Palpatine all have different intentions it makes for greater drama and tension.
They all have different intentions. It’s just that Vader has to kill the Emperor to do what he wants.
The reason you can’t neglect the “I must obey my master” line, is because it is the most powerful thing that drives Vader.
Right there, when Luke surrenders, he has a chance to make a choice, to do what he wants, to unite with his son, so together they can overthrow the Emperor.
Yet he turns his son over to the Emperor, because he must obey his Master.
Even when Luke tries to kill the Emperor, all he has to do, is not to parry the blow. Easiest thing in the world not to do anything, and let others do the work for me.
Yet he couldn’t even do that, and instead he tried to kill his son.
All because he must obey his Master.