After the final part of the Star Wars sequel trilogy, The Rise of Skywalker, came out, it became clear that some changes had been made to the overarching plot since the original premise was laid out in The Force Awakens.
Though nothing was ever confirmed, it was generally felt that Rian Johnson must have decided to take things in a very different direction when he signed on to helm the second film, The Last Jedi, and when J.J. Abrams returned to direct Rise, he was left with no choice but to continue his own arc as best he could while also paying off Johnson's ideas that were introduced in the previous film.
Funnily enough, it's now come to light that one character arc that most fans assumed was present from the very beginning was altered significantly.
During a new interview, Adam Driver admitted that Kylo Ren wasn't originally going to find redemption (he turns his back on the Emperor and reverts back to Ben Solo in The Rise of Skywalker), and was actually going to become more committed to the dark side of The Force as the story progressed.
"I had an overall arc in mind that he wanted to do, which then changed," Driver said. "His idea was almost the opposite journey of Vader, where Vader starts the most confident, the most committed to the Dark Side, and by the last movie he's the most vulnerable, and weak, and he wanted to start at the opposite, where this character was the most confused and vulnerable, and by the end of the three movies would be most committed to the Dark Side."
Ren's redemption was signposted in The Last Jedi when he formed a connection with Rey, and did (arguably) make at least a certain amount of sense since the character started out as the heroic son of Han Solo and Leia Organa before being corrupted. Even so, his fate did feel a bit "Vader 2.0," and seeing a ruthless, irredeemably evil Kylo Ren unleashed in the final movie would have been quite something.
"When it's discovered that the evil Emperor Palpatine did not die at the hands of Darth Vader, the rebels must race against the clock to find out his whereabouts. Finn and Poe lead the Resistance to put a stop to the First Order's plans to form a new Empire, while Rey anticipates her inevitable confrontation with Kylo Ren."