As far as we know, Darth Vader will indeed be in Star Wars: Rogue One. Very credible Star Wars websites such as Making Star Wars have reported that not only will Vader be appearing in the film, but will have a major role. The voice of Vader from the OT (Original Trilogy) and ROTS (Revenge of the Sith) James Earl Jones will be returning to voice the Dark Lord of the Sith, reported Making Star Wars.
So, now that we have knowledge that Vader will be in the film, to what degree will he be? Is what I'm asking. Will he appear as the main antagonist, an antagonist? Or just a brief cameo. More reports suggest he will be featured as the a definite antagonist, if not the main one.
Reports suggested that leaked story screens of Rogue One features Vader decimated entire Rebel battalions. With report suggesting he will throw his lightsaber, and purely destroy rebels unlike shown in the films thus-far.
In the Star Wars: Rogue One teaser trailer, we were shown a robed figure walking into a room that was watched by the Royal Guards of Emperor Palpatine. The figure was also shown kneeling before a Bacta-tank, a tank used for regeneration in the Star Wars Universe.
Now personally, I do not believe this figure is Vader. Darth Vader has never been shown to wear a hood over his suit, most likely this figure is either a high-ranking official in the Empire kneeling before Vader himself.
Overall, I am not certain of what role Lord Vader will have in this film, but as far as we know he will be in it. What do you guys believe his role will be? I would love to hear your feedback in the comments below, thank you.