Everything Palatine Told Anakin Was a Half-Truth
One of the most fascinating parts about the prequel trilogy and Anakin's fall to the dark side is that, while the Jedi are supposed to be his friends, they consistently lie or conceal the truth from him. At the same time, his friend Chancellor Sheev Palpatine always tells the truth - or at least most of the truth - right up to the point where he trusts Anakin with his true identity as Darth Sidious.
The apparent honesty and use of half-truths is especially interesting to pick apart as we look back at Palpatine's story about Darth Plagueis the Wise. First, it's important to remember why Palpatine tells Anakin the story at all. He knows Anakin is devastated over the loss of his mother and fears the loss of Padme. The story is meant to pique Anakin's curiosity over the power of the dark side and prime him for the eventual reveal that, as a Sith Lord, Palpatine can help Anakin achieve that same power so he can save Padme.
But is the Tragedy of Darth Plagueis the Wise the whole truth, or one of Palpatine's half-truths? Looking at the story as, told, it doesn't all quite line-up. How could Plagueis be so powerful that he can stop people from dying, yet foolish enough to let his apprentice kill him in his sleep - especially when he knows killing your master is the path of ascension used by all Sith apprentices?
Taking a step back to look at dark side powers and how they could be used to master immortality, the most logical explanation is that it involves a form of possession or transference of consciousness into a new host body. The Sith had a similar power in the Expanded Universe known as "essence transfer," and Palpatine even used it to live-on in the body of a number of clones in some post-Return of the Jedi stories.
Becoming a Force ghost is an inherently selfless act, so it's not something the Sith can achieve, but it does seem like dominating a new host body is a way Plagueis could prevent his spirit and consciousness from dying out, living forever by hopping from body to body.
So, if The Tragedy of Darth Plagueis the Wise is a half-truth maybe the apprentice did kill the master, but it was Plagueis taking over the body of the apprentice to kill his own aging self, assuming the identity of Palpatine before the events of Stars Wars: The Phantom Menace. And the whole thing could be possible because of a rigid adherence to the Rule of Two.
How Plagueis Could Manipulate the Rule of Two To Achieve Immortality
One of the most fascinating aspects about Palpatine is just how complex and long-term his plan for galactic domination was. He was the ultimate chess master, but some of the essential moves to make his plan work must have been executed long before he entered the scene. Chief among these things is the decision to relocate the main Jedi Temple to Coruscant, where it was built on-top of the site of an old Sith Shrine, whose powers ultimately ended up helping Sidious cloud the minds of the Jedi so they couldn't sense his growing power on the same planet.
The Sith are selfish and only seek to preserve their own power, so its hard to believe the plan was established by a long-dead Sith and executed by his successors, who have no loyalty to his dreams. The only way this plan makes sense is if it was being executed by its own architect, and the Rule of Two would play a fundamental role in seeing that play out.
As Star Wars lore would have it, the Rule of Two was established by Darth Bane after infighting nearly decimated the Sith Order. The Rule of Two ensured that this kind of self-destruction wouldn't happen again by maintaining that there should only ever be two Sith in the galaxy - a master and an apprentice. No more, no less.
The Rule of Two seems like a reliable system, until you consider Plaguis's power over life-and-death could have enabled him to manipulate the Rule of Two to ensure his own survival without any real Sith competition. Instead of training an apprentice who would eventually kill him, he instead could have trained apprentices who he would eventually possess, killing his old body and continuing to live in the body and identity of his former apprentice. It's basically Christopher Nolan's The Prestige but a long time ago in a galaxy far, far away.
Plagueis' Resurrection as Palpatine Explains His Obsession With The Skywalkers
Looking at the Rule of Two and Plagueis in this new context, Palpatine's (or, Plagueis') plans in the prequels makes a lot more sense. He was constantly seeking newer and more powerful apprentices and even seeking out Force-sensitive younglings for his inquisitor program. While it would seem to make sense for him to try to wipe out all other Force users, that's not what he did. He actually continually sought out more and more powerful Force users and tried to bring them under his wing.
He may have finally found his next host in the body of Anakin Skywalker - the Chosen One, but thanks to Obi-Wan Kenobi and a little help from the high ground, that body was summarily ruined. Fortunately, it turned out Anakin Skywalker had a son, so it only makes sense that Palpatine would try to have Luke Skywalker replace his father at Palpatine's side, especially as the Plagueis' Palatine body seemed to be beyond aging at that point and he surely needed a new host. He may have even wanted to replace Vader with Ezra Bridger before he knew Luke existed.
Anakin and Luke thought they defeated the Sith Lord, but as we now know from the trailer for Star Wars: The Rise of Skywalker, Palpatine is alive and well, and with a new super powerful descendant of Anakin Skywalker set loose on the galaxy, he may have found his next host to live on and once again bring Sith Rule upon the galaxy.
- Star Wars 9 / Star Wars: The Rise of Skywalker (2019) release date: Dec 20, 2019