Despite retreading some familiar territory, The Force Awakens marks the biggest leap forward in the Star Wars mythos in a long time. The expanded universe has aptly fleshed out several characters and events, giving the universe it's characteristic depth, but it's near impossible to match the weight of a sequel like this. Episode VII succeeds in reinvigorating the franchise largely because it is the follow up to the original trilogy so many have been craving for so long (there really are fewer drugs more potent then Nostalgia). Yet, the film also lays the framework for future entries to expand upon the series' lore -- providing Episode VIII with several great opportunities.
It seems like a sure bet that at least part of Episode VIII will be dedicated towards Luke training Rey in a manner similar to Yoda training him. It's an interesting role reversal that also provides the chance for Luke to possibly delve deeper into the reasons he went into exile. However, such a "master & apprentice" setup may in concept be a bit too similar to the events of Episode V. Yet, Force Awakens also sets up Kylo Ren to be finishing his training under Supreme Leader Snoke; having one train with the light side as the other more fully embraces the dark side could make for an interesting parallel.
It's both notable and fitting that Kylo Ren is never referred to with the title of "Darth". His emotions are not always in check and it isn't until the end of the movie that he overcomes his temptation to the light side of the force. Despite striving towards it he has yet to become as cold or resolved as his "hero" Darth Vader (something ripe for parody).
It would make sense for him to not have earned such a title yet, but then again that is working from the assumption that he and his master are indeed Sith; a term never used during the movie. The exact nature of their dynamic will hopefully be elaborated upon, as well as how "The Knights of Ren" fit into it. Kylo Ren is supposedly their leader, but it's unclear if they are also proficient with the force and apprentices to Snoke in the same fashion.
With Kylo Ren striving so hard to become the next Darth Vader one might expect for him to be eventually redeemed as Anakin was. Although, with him having murdered Han Solo in cold blood, it could prove difficult to make any sort of atonement palpable and believable. To be given an arc so similar to Anakin's would also be a bit trite, it could prove interesting to see him instead become as remorseless as he envisions Darth Vader to have been.
What's really striking though is his apparent ignorance of Vader's redemption; raising the question of just how well known his final actions are within the Star Wars universe. With Vader and the Emperor dead, the only one to know would presumably be Luke and anyone he might have told. Considering Kylo Ren was once Luke's student, it means he was either never told or he chosen to not believe his former master. If he is truly ignorant of what transpired in the Emperor's Throne Room, exposing it to him would make for an incredibly dramatic reveal.
There's also an argument to be made that like Obi Wan postures in Return of the Jedi that Anakin Skywalker and Darth Vader can be seen as two distinct people; Kylo Ren might have simply chosen to worship one and not the other. As suggested by some of Iain McCaig's concept art from the new book The Art of Star Wars: The Force Awakens by Phil Szostak, Anakin's look in the film would have emphasized this dichotomy, yet also asserting how inseparable they were.
With such art resembling Hayden Christensen, the rumors of a possible appearance of Anakin/Darth Vader in Episode VIII appear a little more believable. Some may cringe at the thought of such a call back to the prequels, but having the actor reprise his role would make sense canonically. Ewan McGregor, who portrayed Obi-wan in Episodes I- III, even make's a brief cameo during Rey's vision. Obi-wan is the one to say, "Rey, these are your first steps." While "Rey" may have been taken from an line spoken by Alec Guinness, the rest was recorded for the movie by McGregor himself.
There may yet be a way for either or both to return, perhaps during a flashback but probably more likely as Force Ghosts. It would be very believable for Luke to have continued communicating with Obi-wan, Yoda, and Anakin after the events of Return Of The Jedi; both while he sought to teach a new generation of jedi and during his days as a hermit.
Considering how Episode VII distanced itself so blatantly from the prequels, one would think there would have to be a compelling reason for having Christensen and/or McGregor reprise their roles. Christensen's return in particular would most likely have to be handled very carefully. Who knows, perhaps if done well it may actually restore some of Anakin's luster lost somewhat by the prequels.
If either return, hopefully it would be to service Rey's expected training under Luke in Episode VIII or even the mystery of her heritage. To no one's surprise there is no shortage of theories in regards to that question. There's the seemingly obvious choice that she is Luke's kid, but others argue that she's Han and/or Leia's kid -- making her Kylo Ren's sister. Some maintain that she really is "no one", someone who's truly of modest origins. However, one of the most interesting and well developed theories is that she is actually the grand daughter of Obi-wan himself.
The argument is that sometime between the events of Episode III and IV Obi-wan fathered a child, who subsequently had Rey sometime after the events of Episode VI. Mr. Sunday Movies, creator of the theory, draws several connections between the two:
- More superficial elements: they share similar outfits and are both fond of and proficient at using the Jedi Mind trick. The sequence in which she is sneaking around Star Killer Base is also reminiscent of when Obi-wan was disabling the Death Star's tractor beam in A New Hope.
- Canonically, Luke would probably be aware if Obi-wan had children (as he is in possession of his journal)
- Daisy Ridley, who plays Rey, has said her isolation is a hint to her origins; possibly meaning that it is meant to echo Obi-wan's exile between Episodes III and IV.
- It would give deeper meaning to his voice appearing in Rey's vision. What's said is also similar to when Obi-wan said to Luke, "You've taken your first step into a larger world."
- Rey's connection to Luke's and Anakin's lightsaber is because Obi-wan was in possession of it as well (as Mr. Sunday Movies points it he actually had longer then both of them combined)
As with many of the theories floating around they do have to be taken with a grain of salt. There is only so much that can be deciphered with evidence that is largely circumstantial. Yet, having her be a descendant of Obi-wan would provide another rationale for the character to return in some regard; and as some have contended it may be time for someone other then a Skywalker to save the galaxy. Only time will tell if it's any true or just really well thought out fan fiction.