Mark Hamill had more than one role in Star Wars 9. The actor's secret role has now been revealed and like The Last Jedi, and it's another voice role. In the previous installment, Hamill provided the voice of Dobbu Scay, the diminutive amphibian gambler who appeared during the Canto Bight Casino scenes. The character resembles a leprechaun and is clearly intoxicated as he mistakes BB-8 for a slot machine, pumping him full of gold coins, which comes in handy later. Hamill took on a more serious role this time around. There are SPOILERS for The Rise of Skywalker below, so read ahead at your own risk.
Luke Skywalker has more of a cameo in The Rise of Skywalker, which is slightly bigger than his role in The Force Awakens. He really only has one scene, which takes place on Ahch-To and then he shows up again at the end of the movie in what looks like an airbrushed mural on an old van from the 1970s. With that being said, Mark Hamill was able to play another role, though most Star Wars fans probably didn't catch it right away.
When we first see The Resistance in The Rise of Skywalker, they're off to meet someone who has some intel about The First Order. That person is the new addition to the franchise, a horned alien named Boolio. Boolio, voiced by Mark Hamill lets them know that there is a mole within the First Order, which in the end gets him killed. It's only a brief part, much like that of Dobbu Scay. While J.J. Abrams voices the new droid, D-0, Hamill should have gotten a bigger voice role and taken on that role too.
Mark Hamill has become an in-demand voice actor over the years with his most famous role arguably being the Joker in Batman: The Animated Series, along with subsequent appearances in other shows, movies, and even in video games. While Hamill is done playing Luke Skywalker for the time being, one can easily see him providing some voices in the future of the Star Wars franchise. In fact, fans should already be looking at The Mandalorian to see if the actor pops up there in the near future. This has not been confirmed, but Jon Favreau should reach out...
The Rise of Skywalker is finally in theaters and the reactions are mixed, which was to be expected. J.J. Abrams was given the task to end the sequel trilogy, along with 40 years-worth of storytelling. In other words, that's a job that not many people would want to take on. Colin Trevorrow is probably sitting back and having a good laugh at the moment as the fans continue to battle each other over the merits of the final installment in the Skywalker Saga. You can head over to StarWars.com to get ticketing info and showtimes in order to see Mark Hamill as Boolio.