The fictionalization of Star Wars: The Increase of Skywalker officially explodes the idea that Palpatine was really Plagueis right all along.
STAR WAR’S EXPLOSION
Star Wars has exploded the favored theory from the growth of Skywalker that Emperor Palpatine was actually Darth Plagueis right along. In Star Wars Episode III – Revenge of the Sith, Palpatine told Anakin Skywalker of his own Sith Master, Darth Plagueis the Wise, who had discovered how to cheat death using the dark side of the Force.
Star Wars: the increase of Skywalker revealed that the key was an ancient Sith power referred to as “Essence Transfer.” this enables a recently-deceased Sith to transfer their spirit to a different vessel; a close-by object or person. It’s much easier to inhabit someone if they’re filled with the dark side, explaining why Palpatine wanted Rey to act in rage and hate; she would be less ready to resist his baleful influence. This ability appears to transform the context of the Sith Rule of Two; it raises the likelihood that every Sith Lord has possessed the body of his or her Apprentice, explaining why the Sith are growing in power over the course of millennia, becoming a malignant imbalance within the Force. Thus Palpatine is himself Plagueis, making his account to Anakin Skywalker supremely ironic. The idea was apparently confirmed by one line of dialogue in Star Wars: the increase of Skywalker when Palpatine boldly proclaimed himself to be the embodiment of “all the Sith.”
STAR WAR’S NOVELISATION
However attractive this theory could also be, however, the novelization of Star Wars: the increase of Skywalker explicitly debunks it. In one key scene, Palpatine remembers how he survived his death:
“Falling… down a huge shaft, the betrayal sharp and stinging, a figure high above, black-clad and helmeted and shrinking fast. His very own apprentice had turned against him, the way he himself had turned against Plagueis… whose secret to immortality he had stolen.
Plagueis had not acted fast enough in his own moment of death. But Sidious, sensing the flickering light in his apprentice, had been ready for years. therefore the falling, dying Emperor called on all the dark power of the Force to thrust his consciousness far, distant to a secret place he had been preparing. His body was dead, an empty vessel, long before it found rock bottom of the shaft, and his mind jolted to new awareness during a new body – a painful one, a short-lived one.”
STAR WAR’S TRANSFORMATION
It seems Essence Transfer was the key to Plagueis’ immortality. That adds another layer of irony and misdirect to Palpatine’s words in Star Wars: Episode III – Revenge of the Sith; He tempted Anakin with the dark side of how to stay Padmé alive when this power would only have allowed Anakin to save lots of himself from death. All the most enthralling lies are half-truths, and Palpatine has always been supremely deceitful.
Amusingly, this changes Charles Soule’s Darth Vader run into a setup for Star Wars: The Rise of Skywalker. That revealed Palpatine had continued researching Essence Transfer after he had become Emperor, and that he had got the mask of a Sith heretic named Lord Momin. Momin had died during a powerful conflagration of Dark Side energy, and his essence had been trapped within the mask he had worn. To be in the presence of Momin’s mask was to fall under the influence of the dark side of the Force, driven to rage and bloodlust, while actually wearing the mask meant you were possessed by his spirit.
The key difference between Palpatine’s Essence Transfer and Lord Momin’s, however, is that the fact Palpatine was ready to possess a clone body that was light-years away, whereas Momin had possessed his own mask. It’s possible the Emperor used a realm referred to as the planet Between Worlds, which he discovered in Star Wars Rebels; that might explain the flare of blue light as Palpatine apparently died, which corresponds with portals to access that mysterious plane of existence.
You can watch the trailer here: