Star Wars has finally revealed just how Supreme Leader Snoke trained Kylo Ren. The sequel trilogy introduced viewers to a galaxy at war once again, but there are still many mysteries about just how that came to be. The films themselves leave lots of gaps, ones that are gradually being filled by various tie-in media including novels and comics.
Charles Soule's miniseries The Rise of Kylo Ren provided many answers. It revealed Ben Solo never truly chose the dark side at all, but rather found himself imprisoned to it as a result of the resurrected Emperor's schemes. Working through his puppet Snoke, Palpatine had manipulated Ben all his life. Finally, one dark day, Palpatine seems to have allowed Luke Skywalker to sense his presence in the Force. Luke's reaction was instinctive but misguided, as he lit his lightsaber over his sleeping nephew. Ben awoke, horrified to see his uncle standing over him apparently about to execute him, and he naturally lashed out. With Luke defeated, the Emperor unleashed a Force Storm upon the Jedi Temple, killing almost all the Jedi in one devastating attack. Ben was blamed for it, and – pursued by the last surviving Jedi Knights – he was left no choice but to go to Snoke for guidance.
Lucasfilm has recently published a biography of the Skywalker family by Kristin Baver, Skywalker: A Family At War, and it finally details Snoke's training of the man who had just come to call himself Kylo Ren. Snoke's methods mirrored those of Master Yoda in the High Republic Era, as he travelled the galaxy with his new student in order to shape him as he wished. "It was during this time that Snoke administered a series of tests to ensure that Kylo Ren would be molded to obey without question," the biography notes. He taught Kylo Ren to unleash the raw power of his emotions and allow his anger and rage to fuel his power in the dark side of the Force. According to Snoke, he was teaching Kylo Ren true freedom; in reality, he was ensuring the young man was a slave to his emotions.
The Star Wars: Age of Resistance - Snoke one-shot showed how Snoke even subverted Luke Skywalker's own training in order to corrupt Kylo Ren. He took Kylo Ren to the Force vergence on Dagobah, where his apprentice was granted a vision of Luke Skywalker. Furious, Kylo Ren actually destroyed that cave of the dark side, much to Snoke's displeasure; he had intended to use that cave to corrupt others as well. Still, this display of raw power was nonetheless impressive.
There are still many unanswered questions about Kylo Ren's training in the dark side. Baver's biography does not, for example, tell us just how Ben Solo first met Snoke; clearly Lucasfilm either is not ready to reveal that just yet, or the Story Group hasn't decided. At least some of the gaps have been filled, however, and we are gradually learning just how the son of Han and Leia became one of the most dangerous villains in the Star Wars saga.
