Spoilers for The Force Awakens below
Darth Vader is my favourite Star Wars character but it's his son Luke Skywalker's story that for best epitomizes the mythic nature of the Star Wars saga. The original trilogy is about Luke's journey from a Tatootine farm-boy who doesn't know the legacy of his namesake to a Jedi who redeems his father and helps save the galaxy. When we get to The Force Awakens Luke has become a figure of legend. Rey believes he's just a myth. One can imagine that children in the post-Return of the Jedi galaxy have grown up with stories of Luke, Han Solo and Princess Leia. This is appropriate considering the fairy tale nature of the saga.
What intrigues me most about the The Last Jedi trailer is Luke saying the Jedi must come to an end. It appears that Luke is a more cynical character 30 years since Return of the Jedi's ending. I can't help but think of Luke telling Obi-Wan Kenobi he wanted to about the Force and become a Jedi like his father; and later, telling the Emperor he'll never turn to the dark side, that he is a Jedi, like his father before him. Now, what he once strove to become may not have any positive meaning for him anymore.
The ending of Return of Jedi left Luke as the person who would rebuild the Jedi Order, albeit likely different in certain ways from what became before. In The Force Awakens we know that Luke has attempted to train new Jedi but Ben Solo- Han's son and Luke's nephew- and the Knights of Ren killed Luke's pupils. This sent Luke in to exile like Obi-Wan and Yoda- and likely led to a new outlook on the relevancy and purpose of the Jedi, thinking beyond the dogma of both the Jedi and the Sith. With the Jedi being eliminated twice perhaps Luke is taking that as a sign from the Force. Maybe the galaxy would be better without dogmatic religions. What I'm curious about is that will affect the role of force users in the saga post this new trilogy.
Also: Supreme Leader Snoke and Ben (now calling himself Kylo Ren) aren't Sith, so they themselves represent a different type of dark side user. However, Ren still worships his grandfather who was a Sith.
I'm also wondering what Luke is going to be teaching Rey specifically and how her arc will proceed People have theorized that she will go to the dark side, which would be a bold choice. I enjoyed The Force Awakens but I feel this film will explore new mythological territory in regards to the Star Wars universe; like The Empire Strikes Back, this middle chapter will deepen and redefine what came before, leading us in to the conclusion of this trilogy.
So, what are your theories on Luke's possible story in The Last Jedi. Comment below and let me know.