WARNING: The following article contains major spoilers for director Rian Johnson’s Star Wars: The Last Jedi, in theaters now.
The pivotal flashback scenes in Star Wars: The Last Jedi that showed why Ben Solo turned on Luke Skywalker were late additions in the script according to director Rian Johnson. In The Art of Star Wars: The Last Jedi, Johnson indicated that these scenes were added to create more drama and impact for when Rey finds out exactly what drove Ben to forsake the Jedi Order.
“The three flashbacks were a late addition -- one of the last things that went into the script before we started shooting," Johnson said. "It’s similar to Rashomon, but the actual story motivation was that I wanted some harder kick to Rey’s turn: ‘You didn’t tell me this.’ I wanted some harder line that was crossed -- a more defined thing that we could actually see -- between Luke and Kylo."
In the movie, the three flashbacks start firstly from Luke's perspective, where he implies Ben simply lost his temper because of his uncontrollable anger; then Kylo's perspective, where he tells Rey that Luke was going to kill him in his sleep; and lastly, once more from Luke. Only this time Rey finds out what really happened, which was that Luke did indeed contemplate killing the boy but only because he used to Force to sense the killer that Ben was going to become.
"I didn’t want to do a big flashback," Johnson said. "So one flashback that you repeat three times but that’s just one moment seemed more right. Ultimately, the only one who lies is Luke, in the very first flashback, where he omits the fact that he had a lightsaber in his hand. Kylo is basically telling the truth about his perception of the moment."
Luke quickly realized the error of his ways, but Ben immediately assumed the worst when he saw Luke's lightsaber and engaged him in battle. This ultimately led to Ben slaughtering the rest of Luke's charges, burning the temple down, falling under Snoke's influence and taking some Jedi survivors as the Knights of Ren. In other words, Luke's rash actions drove Ben to become Kylo Ren.
Written and directed by Rian Johnson, Star Wars: The Last Jedi stars Mark Hamill as Luke Skywalker, Daisy Ridley as Rey, John Boyega as Finn, Adam Driver as Kylo Ren, Oscar Isaac as Poe Dameron, Andy Serkis as Supreme Leader Snoke, Domhnall Gleeson as General Hux and Gwendoline Christie as Captain Phasma.