Luke Skywalker's story in Star Wars: The Last Jedi is one of the most talked about things in the entire franchise now. However, the way Mark Hamill talks about it is completely unique. The Luke Skywalker actor recently posted the panels from the recent Star Wars: The Last Jedi comic book which show Luke's final moments, and the man behind the Jedi compares Luke's (apparent) death to that of an addict who dies at the hands of a drug. Give it a look.
At this point, even if you somehow haven't actually seen Star Wars: The Last Jedi, you likely know how it ends for Luke Skywalker. Luke appears to face down Kylo Ren only for it to be discovered that Luke is only projecting an image of himself from across the stars. The effort is extreme, however, and Luke is wiped out when it's done. Luke takes his place watching a binary sun as he fades away.
While the comparison to a drug addict is certainly an extreme one, it's difficult to argue that it's not apt. Luke Skywalker had cut himself off from the Force for years. When we see him in The Last Jedi he's not using his power at all, even passively. As Hamill says, Luke goes from cold turkey to a massive overdose.
There is certainly an irony to the fact that Luke disappears after giving in to the thing he's been neglecting for so long. Of course, exactly what that means isn't entirely clear. One thing that the Star Wars: The Last Jedi does do is make it plain that Luke hasn't simply died, but has joined "a larger world." He has become part of the Force in the same way that Ob-Wan Kenobi and Yoda have done before him. This, combined with the fact that Mark Hamill is confirmed to appear in Star Wars: Episode IX would indicate that we'll see Luke again as a Force Ghost or something similar.
Luke Skywalker's story in The Last Jedi is still a hot-button topic among fans. Some fans felt very strongly that a Luke Skywalker who nearly gave in to the dark side and killed his own nephew was the wrong direction for the character, while others felt that seeing Luke continue the struggle with doubt that we saw in Star Wars: Return of the Jedi made a lot of sense. Even Mark Hamill himself has said that he wasn't entirely on board with the story as written at first, though he's come to its defense since.
The battle over Luke's fate continues. The responses to Mark Hamill's tweet are full of people debating the decisions all over again. Not only do people both praise and criticize Luke's end, but both sides of the argument are also using the tweet as some sort of endorsement by Hamill of their particular point of view. It seems this fight won't be ending anytime soon.