The appearance of "Dark Rey" in the latest trailer for Star Wars: The Rise of Skywalker showcases a theme that runs through the entire saga: the existence of duality, the value of acknowledging its presence and the importance of finding balance.
At the end of The Last Jedi, Rey emerged heartbroken but otherwise unscathed, doubling down on her determination to stick to the Light Side of the Force. But her path is following the footprints left by Anakin and Luke. That places her on a collision course with Kylo Ren, whose journey started in the opposite direction, but also with her barely explored potential for inner darkness.
Rey's encounter with her shadowy self could take three forms, two of which have already happened: She could have to fight her opposite character archetype (Kylo Ren in The Force Awakens), or she could have to face a metaphorical version of her dark side (like she did in the Ahch-To cave in The Last Jedi). That leaves a third possible confrontation for The Rise of Skywalker, dueling her genetically identical Dark Twin. So, let’s explore the different ways in which this Dark Double could exist.
Dark Rey could be a clone of Rey. No, stop, don't click away; we know that clones are such a cliché that even the First Order grew tired of them and decided to abduct child soldiers for variety's sake.
But, also to be fair, their continued existence has also been lampshaded by Kylo Ren remarking that the First Order would be better off with absolutely loyal clones; Episode IX's Sith Troopers are rumored to come from an area of the galaxy renowned for its cloning facilities, and Rey's cave vision in Episode VIII featured her infinite reflections, a scene that made many think that she might have been a stray from a cloning program.
Clones would also echo some of the Legends plotlines concerning Palpatine's return from the dead; an evil Luuke Skywalker (who was cloned from Luke's hand), and the Galen Marek/Starkiller clones that apprenticed under Darth Vader in The Force Unleashed.
The main issue with the clone theory is that the timing doesn't quite work. The Emperor (supposedly) died at the Battle of Endor, and Rey wasn't born until roughly 10 years later. Why would Palpatine want to start cloning Force-sensitive women a decade after his own death? However, should the Emperor have left behind a precise contingency plan, one of his loyalists could have, theoretically, followed his orders, found an adequate "Prime Rey," injected the embryos with some midi-chlorian-friendly enzymes and, voilá, Sith clones.
Rey could have been implanted into her "nobody" junk-trader birth mother, or she could have been kidnapped as a baby by the same people who abandoned her, or even be the non-modified Rey, obtained in a negotiation, just like Jango Fett secured Bobba when he agreed to lend his genetic material on Kamino.
There's also the fact that The Rise of Skywalker features Zorii Bliss, a high-profile bounty hunter, played by Keri Russell, a J.J. Abrams favorite who looks strikingly similar to Daisy Ridley and would have been around 13 or 14 years old when Rey was born.
Again, this is sheer speculation, but if the Star Wars movies have to echo each other, clones obtained from the genetic material of a bounty hunter would be well within the metric parameters.
Now, let's take a look at the much less operationally expensive theory of Rey having a literal Dark Twin.
In Marvel's Darth Vader: Dark Lord of the Sith series, Vader enters the world of the dead and sees that Darth Sidious manipulated the Force to impregnate Shmi, his mother. Shmi was a nobody from a backwater planet, just like Rey's parents. In other words, perfect anonymous guinea pigs for Palpatine's experiments.
If we learned anything from the Empire's obsession with Death Stars, it was that the Emperor always planned for a back-up.
Just like the multiple Death Stars, it's very likely that he also might have tried to create multiple Force babies and Anakin was just the one that popped up first. Think of it as IVF conducted by the Dark Side: a doctor would never implant just one embryo, they would throw in at least two or three and hope that one takes.
Maybe more of these Force-powerful children were born but none of them were found by the Jedi before Anakin, and their potential remained locked -- just like Rey's in The Force Awakens.
In this case, timing is less of an issue. On the one hand, Palpatine could have been manipulating the Force to create these back-up apprentices for a long time before and after he knew of Anakin's existence. Besides, who's to say that Palpatine can't Force-impregnate people from the other side of the veil? Vader's visions took place in the realm of the dead, and in Rebels, Palpatine almost gained access to the World between Worlds. As far as we know, the Galaxy could be overflowing with Palpatine's younglings.
Finally, even if Palpatine had stopped creating Force babies after Anakin appeared, Rey and her potential Dark Twin could very well be the descendants of one of these kids, just like Ben Solo is the grandson of Anakin Skywalker.
The main issue here is that it is a little late in the game to introduce a secret sister that Rey -- or anyone -- has never mentioned before. Sure, Rey also hasn't denied the existence of a twin sister, but after The Last Jedi's reveal of her true parents, the Evil Twin trope, even though there is a precedent for it, would narratively come a bit out of the blue in the sequel series.
Directed and co-written by J.J. Abrams, Star Wars: The Rise of Skywalkerstars Daisy Ridley, Adam Driver, John Boyega, Oscar Isaac, Lupita Nyong’o, Domhnall Gleeson, Kelly Marie Tran, Joonas Suotamo, Billie Lourd, Keri Russell, Matt Smith, Anthony Daniels, Mark Hamill, Billy Dee Williams and Carrie Fisher, with Naomi Ackie and Richard E. Grant. The film arrives on Dec. 20.