Star Wars set up two great villains for Star Wars' lowest Rotten Tomatoes score for a live-action movie and became the least-profitable installment in the trilogy. While The Rise of Skywalker does have its fair share of fans, some found it to be a disappointing conclusion to the Skywalker saga.
One of the larger overarching issues in The Rise of Skywalker is Emperor Palpatine. After being absent for the previous two films, Palpatine returned in The Rise of Skywalker, but his role left viewers with more questions than satisfying answers. The fact much of Palpatine's role was cleared up via tie-in publications illustrates Disney knew they got it wrong and attempted to course-correct months later. There was much hype surrounding Palpatine's surprising comeback (generating plenty of fan theories), but it was ultimately a bit of a letdown.
On the surface, bringing Palpatine back into the fold made sense. It made him the singular thread that tied all three trilogies together and had him be the overarching villain for the entire series. However, by using Palpatine, director J.J. Abrams and company neglected a pair of villains that arguably would have been stronger and more organic within the context of the sequel trilogy: Kylo Ren and Dark Rey.
The Rise of Skywalker Wasted Kylo Ren's Arc
When the sequel trilogy started, Kylo Ren was the dark side apprentice of Supreme Leader Snoke, obsessed with being the heir apparent to Darth Vader. Kylo and Snoke's dynamic was similar to Vader and the Emperor at the start, but it followed a very different trajectory. One of The Last Jedi's greatest twists is Kylo killing Snoke in the throne room, upending the First Order hierarchy and appointing himself as the new Supreme Leader. By the time The Last Jedi ended, Kylo had sworn to destroy Rey and whatever was left of the Resistance, seemingly cementing his descent into evil. If The Rise of Skywalker was to use The Last Jedi was a jumping off point, depicting Kylo Ren as the main villain was arguably the way to go.
However, Palpatine's late return interrupted Kylo's arc and instead repeated beats from the previous films. Once again, Kylo found himself under a power powerful dark side master, scheming his way to get ahead. What made this disappointing is that rather than being a natural progression of Kylo's character, it put him in a bit of a holding pattern until it was time for Ben Solo's redemption. There was potential here to make Kylo's story all the more tragic and heartbreaking by having the literal descendant of Rebellion heroes become the most vile person in the galaxy and it would have been something different for Star Wars to tackle as a whole. While it's true audiences witnessed Anakin's fall to the dark side in the prequels, Kylo was introduced as a villain who felt the pull of the light. Instead of being the inverse of Luke, Kylo's ultimate arc was similar to Vader's redemption, repeating something viewers had already seen.
Dark Rey Was Heavily Teased (& Then Wasted)
One of the more striking images in the Rise of Skywalker marketing campaign was Dark Rey wielding a red double-bladed lightsaber. It made for an eye-catching money shot to end a trailer and invariably got audiences excited about what was in store. To be fair, many assumed (correctly) that this tease would amount to nothing more than a vision sequence. After all, especially given J.J. Abrams' penchant for mystery boxes, it seemed unlikely there would be a massive spoiler like Rey going to the dark side in Rise of Skywalker marketing materials (Palpatine's physical appearance was held back for the length of the campaign). Still, there were those who felt the Dark Rey shot was laying the groundwork for something bigger in the movie.
Throughout The Rise of Skywalker, Rey has an internal struggle where she's afraid of what she's capable of. This is exacerbated by learning she is Emperor Palpatine's granddaughter, and part of her believes she is destined to sit on the Sith throne. Dark Rey is a manifestation of that concern, but doesn't amount to much in the movie. Again, Dark Rey being a vision was always the prevailing belief, but that's part of what made her minimal Rise of Skywalker screen time disappointing. The filmmakers could have attempted to do something different or unique with the concept, but instead just took the standard path. This might be a situation where fan theories set viewers up for a letdown (though Daisy Ridley hinted Dark Rey was real), though the character could have been cut from the film and not made much of a difference.
How Rise of Skywalker Should've Used Kylo Ren & Dark Rey
The easiest way to improve both of these would-be villains would be to eliminate Palpatine, who arguably mucked up Rey and Kylo Ren's compelling dynamic anyway. By removing Palpatine from the film, it allows Kylo Ren to be the undisputed principal antagonist in The Rise of Skywalker and the ultimate threat that must be stopped (which was the plan in Colin Trevorrow's scrapped Duel of the Fates). That would have been a more interesting trajectory for the character; Kylo was established as one of the most complex characters in the Star Wars movies and it would have been fascinating to see Adam Driver work with that kind of material. The Rise of Skywalker frankly doesn't give Driver much to do as an actor, and there's an extended stretch where he disappears from the movie.
As for Dark Rey, there was a chance here for a genuine twist that would have given The Rise of Skywalker more narrative heft. The final film merely scratches the surface of Rey's underlying darkness, leaving the thread with a ton of untapped potential. Selling Rey's turn might have been difficult since she seemed set on the light path at the end of The Last Jedi, but that doesn't make this concept any less tempting. If anything, it could have added to The Last Jedi's critique of binary Force allegiances, making a greater point about that theme. Perhaps Rey could have dabbled in the dark side to gain an advantage over the First Order and struggled to maintain a balance. Even if Rey didn't do a total 180 a la Anakin in Revenge of the Sith, giving Dark Rey a greater role in The Rise of Skywalker would have been more interesting. She'd likely turn back, but the movie would still have an opportunity to explore the consequences - be it via a time jump or other means.