Star Wars: The Last Jedi was both praised and criticized for the way it took Star Wars in new directions, but that doesn't mean it wasn't strongly influenced by other parts of the franchise. Recently, a fan asked Rian Johnson his thoughts on the Mortis storyline from the Star Wars: The Clone Wars animated series, and Johnson revealed that he had specifically rewatched the episodes early in his process of writing his script for The Last Jedi.
The storyline in question from Star Wars: The Clone Wars has Anakin Skywalker, Obi-Wan Kenobi, and Asoka Tano transported to a mysterious world called Mortis that was inhabited by only three people, The Son, powerful in the Dark Side of the Force, The Daughter, equally powerful in the Light Side, and The Father, who kept the balance between them. The Father has brought Anakin to the land in hopes he will replace The Father as the keeper of balance once he dies. Eventually, all three of them actually die, which, in its own way, still keeps the balance in the Force.
While Rian Johnson doesn't talk specifically about how these episodes influenced him, it's not hard to see how. Johnson does call the episodes "gorgeous and boundary-pushing" and those are certainly both things that would have to be said about Star Wars: The Last Jedi. While arguments still abound about the movie overall, nobody is claiming the film isn't beautiful or that Rian Johnson didn't push the limits of what Star Wars had been up to that point. The entire idea of Mortis, a sort of living manifestation of the Force, was something that had never been hinted at in the franchise before. It's entire existence potentially changes quite a lot about how you view the Force and Star Wars as a whole.
It's also not hard to see a connection between Kylo Ren and Rey and the Son and Daughter characters from The Clone Wars. Each one has fully embraced their side of the Force, and while there may not be a familial relationship between them, there is clearly a connection. In this analogy, I suppose Luke Skywalker becomes the Father, though a somewhat absentee one.
It shows just how big Star Wars has become, when something like The Clone Wars, an animated series that spun off from the prequel trilogy, is able to come into its own to the point where it, in turn, inspires the next generation of films. Perhaps the series will continue to do so in the future, as it was recently announced that Star Wars: The Clone Wars will be returning with new seasons as part of Disney's upcoming streaming service.
