While it’s true to the attitude he has in Star Wars: A New Hope, I can’t help but think one scene showing Vader’s contempt for Palpatine, or feeling of loss for his wife would’ve gone a long way to further show that there was someone who could be saved in that suit.
Even modern movies have skewed away from making Darth Vader even somewhat of a gray character – just look at Rogue One: A Star Wars Story and his terrifying rampage in the movie’s final minutes.
You can help alter that image and add to our larger perception of Vader as a character by putting him at the center of his own feature.