This may be painful for some to hear but Christensen and Sebastian Shaw are the only one's to play Vader without a mask (that I'm aware of). They're the only one's that we can put a human face to for Vader.
For me, Vader is not Vader until he gets the mask. Christensen and Shaw played only Anakin Skywalker, not Vader.
When Anakin fought Obi-Wan on Mustafar, there was still a chance that he would turn back to the light side. For me, he was still Anakin at that point. When Luke removed Vader's helmet, Vader was gone and Anakin had come back.
With the mask came the breathing, the voice and the mannerisms. Muir, Burrt, Jones and Prowse each contributed with one component, and Vader would not have been Vader without
any of them.
Symbolically it doesn't make sense to show young Anakin as the ghost at the end.
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Personally. I like it how it was originally. It does not connect to a selfish, whiny, arrogant, mass-murdering brat. It connects to the scarred, flawed man Luke saw when he took off the helmet.
I absolutely agree. I have more arguments for Shaw:
Luke is the only one in the party seeing the ghosts. The images are in
his mind and it would not make sense for him to see an incarnation of Anakin Skywalker that he had not seen before.
Shaw is also successfully projecting the image of being
a proud father. That is something that Christensen did not do, and with his youth would not be able to do. Instead, Christensen looked
embarrassed to even be there. It is as if he did not agree with Lucas for putting him in the new revision...