By now, it's no secret that Mark Hamill is in the star-studded cast of The Rise of Skywalker, returning to his iconic post as Luke Skywalker. There have been many convincing theories that Luke pops up as a clone in the final installation of the trilogy. Drawing on Timothy Zahn's 1993 Star Wars novel The Last Command, some Star Wars enthusiasts believed that his severed hand was salvaged for cloneable DNA. However, Luke comes back to the movie in a much less complicated way. As you may have guessed, Luke returns as a Force spirit, guiding Rey as she buckles down to battle Palpatine.
We first feel Luke's presence off-screen, as Rey sifts through his Jedi texts and learns about a Sith Wayfinder that will help her find Palpatine, who is very shockingly not dead. There are, suffice to say, a few bumps along the way. Kylo Ren reveals to Rey that she's Palpatine's granddaughter. He doesn't leave her alone after that, of course. Even when she tracks down the Wayfinder at the remains of the second Death Star, Kylo destroys it when they battle. She mortally wounds him in the duel but heals him immediately while sensing Leia's death.
Distraught, Rey uses Kylo's ship to get to Ahch-To, where she tosses her lightsaber. Luke, emerging as a Force ghost, catches it and says that a lightsaber should be treated with more respect. (Which, the Internet saw as shade towards The Last Jedi.) Luke shares words of wisdom with Rey, prompting her to continue her quest against Palpatine and giving her Leia's lightsaber and his X-wing. Rey sets off for Exegol and uses the Wayfinder from Kylo's ship.
Luke pops up a few more times, but his appearances aren't necessarily huge plot twists. In her final battle with Palpatine, Rey draws upon the strength of Force wielders before her, hearing Jedi voices guide her. The last voice she hears is Luke's, who says, "Rey, the Force will be with you. Always."
At the very end of the movie, Rey goes to Tatooine to bury Luke and Leia's lightsabers. When a local asks her what her name is, she replies that her name is Rey Skywalker, Luke and Leia watching her as spirits.