Near the end of Star Wars: The Force Awakens, Kylo Ren (Adam Driver) suffers a facial injury during a lightsaber battle with Rey (Daisy Ridley) and Finn (John Boyega). The injury resulted in a severe scar running along the left side of his face, cutting just across the inner part of his cheek.
While the exact placement of Kylo's scar shifted a little bit by the time audiences saw him next in Star Wars: The Last Jedi -- crossing over his eye and into his eyebrow rather than his nose and center of his forehead -- the general placement on his cheek remained the same and in a place that has a significant connection to his father, Han Solo (Harrison Ford).
In The Force Awakens, Han confronts Kylo, his son formerly known as Ben Solo, on Starkiller Base and implores him to abandon the Dark Side. During the confrontation, Han touches Kylo’s face almost exactly where he will be injured a short time later by Rey and Finn. As a sharp-eyed fan on Reddit pointed out, Kylo's scar now sits in the last place his father touched him, marking not only his defeat on Starkiller Base, but his final moments with his father.
The matching placement of the scar is significant because Han's death -- or, more specifically, Kylo's murdering of his father -- continues to haunt Kylo. Not only is he still rattled enough by his actions, but he is also unable to fire on the lead Resistance ship and kill his mother, General Leia Organa in The Last Jedi. It's also something that Supreme Leader Snoke and pretty much everyone else who encounters Kylo picks up on, but it's Snoke that makes the most direct reference to the scar even as he berates his apprentice for failing to live up to the potential of Darth Vader.
While it's not clear if the scar and Han's last touch to Kylo's cheek are intentionally linked, it would make for a nice detail, showing that Kylo will forever be marked by the choices he's made regarding his descent into the Dark Side. What is clear is that the more general placement of the scar, particularly when it comes to the shift from crossing Kylo's nose in The Force Awakens as opposed to his eyebrow in The Last Jedi, was intentional. The Last Jedi director Rian Johnson revealed on Twitter months ahead of the film's release that he had shifted the location of the scar for aesthetic reasons, stating that the original location "honestly looked goofy running straight up the bridge of his nose."
Star Wars: The Last Jedi is in theaters now.