In the original Star Wars trilogy, possibly science fictions biggest villain Darth Vader was brought to the screen with the teamwork of the towering 6' 6" British actor David Prowse in the suit and American actor and Hollywood legend James Earl Jones supplying the voice. British actor, the late Sebastian Shaw also portrayed the character for the end of return of the Jedi, when Vaders mask is removed and later when Anakin Skywalker is seen as a Force Ghost (original editions only). For the much-scorned prequel trilogy the characters only two appearances were portrayed by actor Hayden Christensen, whom had played Anakin Skywalker throughout Episodes II and III. At 6' Christensen is somewhat short for the role, but alas it was only for two scenes... or was it?
A rumor sourced from MakingStarWars claims the young American actor, whose career has failed to bloom since his appearances in the prequel trilogy, may be returning to Star Wars to portray Darth Vader in Rian Johnson's Star Wars Episode VIII. This is on top of rumors that the Sith Lord may also make an appearance in Garth Edwards' Rogue One. Reportedly Christensen is being trained by a team in the UK in preparation, though there are no concrete details as to the nature of his appearance. Speculation seems to have risen that he may be returning as Vader thanks to one of the villains suits being seen in the effects shop in the studios (Pinewood or Sheperton we're presuming).
While Hayden Christensen returning as Darth Vader would surely upset haters of the prequel trilogy, the actor along with his British co-star Ewan Mcgregor did become greatly adept with the prop used on set for the Lightsabre. That said, Darth Vader's lightsabre style was much more reserved and calculated that Anakins twists, twirls and poses in the prequel trilogy. And, IF Darth Vader was to return to the big screen filmmakers would only need a competent 6' 6" performance actor within the suit and the magnificent vocal talents of James Earl Jones.
Of course there is a high probability that Christensen may just be returning to portray the Force Ghost of Anakin Skywalker, acting in a similar vein to Sir Alec Guiness' mentor role as Obi-Wan Kenobi in the Empire Strikes Back and Return of the Jedi, mostly likely guiding and/or warning his son Luke of the dangers that lie ahead.