Palpatine's Manipulation of Ben Solo
Star Wars: The Rise of Skywalker secretly hid the real reason behind Palpatine's targeting of Ben Solo as his apprentice. Palpatine's post-Return of the Jedi Star Wars timeline has slowly been revealed since 2019's The Rise of Skywalker. The evil Emperor and his followers spent decades perfecting the process of cloning before Star Wars' First Order timeline transitioned into the Final Order, allowing Palpatine to attempt to regain control of the galaxy once more.
Luke Skywalker and Lando Calrissian in the sequels either side of the First Order logo
During this plan, one of Palpatine's steps was to convert the young Ben Solo to his side via the deceit of Supreme Leader Snoke. As was confirmed by Luke Skywalker's Star Wars timeline in The Last Jedi, Snoke had begun corrupting Ben long before the latter's Jedi training had begun. Thus, the origins of Kylo Ren were brought about and, while it may not be made overtly clear in the film, extended material surrounding Star Wars: The Rise of Skywalker reveals a hidden reason behind Palpatine's manipulation of the young Ben Solo.
Leia with her blue lightsaber and Kylo Ren with his red lightsaber in Star Wars with Palpatine between them
The First Order's Targeting of Rebel Leaders' Children
In Star Wars: The Rise of Skywalker: Expanded Edition, an adult novelization of the 2019 film, it was confirmed that the early First Order targeted the children of former leaders of the Rebel Alliance. This happened to the likes of Lando Calrissian whose daughter was kidnapped when she was two years old. This was also highlighted in the 2022 novel Shadow of the Sith which provides more context to Lando's journey in The Rise of Skywalker.
Therefore, this can be attributed to Palpatine's focus on Ben Solo. As is known from the Star Wars original trilogy, Han Solo and Leia Organa were two of the primary leaders of the Rebel Alliance. This would have caused Ben Solo to be a big person of interest regarding the First Order and explains why Palpatine sent Snoke to manipulate the child of Han and Leia to the dark side.
Ben Solo's Force Power and Its Significance
Moreover, Ben Solo had an incredibly strong aptitude for the Force. This was always expected given Ben Solo's bloodline with his mother being Leia and grandfather being Anakin Skywalker, the Chosen One of the Force. Ben's overwhelming power in the force was likely the primary reason for Palpatine wishing to turn him to the dark side, though it helped that recruiting him also undermined two of the Rebel Alliance's biggest heroes.
Furthermore, not only does Palpatine's targeting of Ben only undermine Han and Leia, but Luke Skywalker as well. Luke saw the potential in Ben which led to the latter becoming a main student of the former's Jedi Order. The fallout of this was explored in the sequel trilogy, with Palpatine's manipulation of Ben's Force power to the dark side being the main catalyst of the destruction of Luke's temple. All of this even further explains why Ben was turned into Kylo Ren by Palpatine as hinted at in Star Wars: The Rise of Skywalker.
