Luke Skywalker was the hero of the Original Trilogy. The former farm-boy turned Jedi Master was the hero every kid in the late 70s and early 80s wanted to be. He was the heart and soul of Episodes IV-VI, so it was surprising to see him basically left out of The Force Awakens. He put himself in self-exile and the whole plot of the film involves the map that leads to him and the two forces trying to get it for different reasons. Rey gets there in the end and we see Luke for all of thirty seconds before the movie ends.
Many people had issues with how Luke was portrayed in The Last Jedi. That didn’t really bother me. We all get to a point in life when we get a bit jaded and crusty around the edges. Luke was clearly that after failing to resurrect the Jedi Order and losing his nephew to the Dark Side. He put himself in exile and basically wanted to live out life alone. What bothered me was the moment he thought about killing Ben Solo.
Original Trilogy Luke would never do that. He saw the redemption of one of the evilest men in the galaxy in Darth Vader. Why he wouldn’t think this boy could be redeemed and had to be killed was completely out of character. Luke simply would never think of killing Han and Leia’s son and his own nephew. That would basically send him down the path to the Dark Side, which he already had shown strong enough to resist.
Luke then dies in Episode VIII by Force projecting himself across the galaxy. He saves the Resistance by doing this and helps spark hope across the galaxy. He returns in The Rise of Skywalker as a Force ghost, nudging Rey to her destiny. Using Luke sparingly and then changing the core of his character was an odd decision on the part of those in charge of the Sequel Trilogy, and is something that will be debated heavily for years to come.