Summary
Star Warshas given the Sith one Force power that makesEmperor Palpatinealmost unbeatable. For a thousand years, the Jedi believed the Sith to be extinct. In reality, the Sith hid in the shadows, limiting their number according to theRule of Two- a mandate that requires there to be only two Sith at any one time, a master and an apprentice. The Rule of Two was established by Darth Bane, and he believed it would ensure every Sith was greater than their master.
The Jedi learned just how dangerous the Sith were inStar Wars: Episode III - Revenge of the Sith. Mace Windu led two other Jedi Masters to arrest Palpatine, but he killed two of them with ease. Later, Master Yoda engaged Darth Sidious in a one-on-one duel, swiftly discovering he was outclassed. This point is driven home inMatt Stover’s novelization ofRevenge of the Sith, which portrays Yoda’s shock as he realizes the Sith have evolved and the Jedi remained static. But now, 19 years afterRevenge of the Sith,Star Warshas revealed just why Palpatine was so unbeatable.

All 39 Sith Lords In Star Wars Canon
The greatest villains of Star Wars, the Sith are the Jedi’s most fearsome enemies. Here are all 36 Dark Lords of the Sith revealed to date.
The Acolyte Made The Sith So Much More Dangerous
Introducing a new Force power
The Acolytemay have been canceled, but one thing’s for sure; the Disney+ TV show featured some of the best lightsaber choreography ever seen inStar Wars. Set a century before the Skywalker saga, at the end of the Jedi Order’s golden age, it saw a group of Jedi discover the existence of a mysterious Sith Lord. Played by Manny Jacinto,The Acolyte’s Sith Lord- officially known only as the Stranger - was determined to ensure his existence remained a secret. InThe Acolyteepisode 5, he took on the Jedi in a devastating battle.
This dark side power explains why, a century later, Palpatine would be able to effortlessly kill two Jedi Masters in battle.

There had never been anything quite like it inStar Warsbefore; a live-action clash between a large group of Jedi and a single Sith, who lashed out with brutal efficiency. Most troubling of all, though, was the fact that he demonstrated a subtle and dangerousForce powerthat gave him in edge in combat; he got into his enemies' minds, confusing them, making them doubt themselves, slowing their reactions. This dark side power explains why, a century later, Palpatine would be able to effortlessly kill two Jedi Masters in battle.
Palpatine Could Only Be Defeated Through Spontaneous Reaction, Rather Than Strategy
We now understand why he lost
Return of the Jediarguably sets up this Force power, because Palpatine is clearly exploring Luke Skywalker’s thoughts and emotions all the way through their encounter.The Acolytetakes an idea that was already present, though, and effectively weaponizes it- just as the Sith would do. It becomes the secret to the near-invincibility of the Sith. But it also explains why Palpatine could only be defeated through something truly spontaneous - as seen in bothReturn of the JediandStar Wars: The Rise of Skywalker.
As powerful as he may be in the dark side, Palpatine’s vision of the future was clouded by the light. He couldn’t envision a reality in which Darth Vader turned on him because of love, not hate, and so was wrong-footed when his apprentice attacked him in Luke’s defense. Likewise, he had no idea the spirits of the Jedi would come to Rey’s assistance on Exegol, meaning he couldn’t anticipate her defense. The Sith really are almost unbeatable inStar Wars- but they still have a major weakness.
Emperor Palpatine / Darth Sidious
The senator for Naboo, Palpatine rose to power and influence during the dying days of the Republic. In reality, his public persona was just a mask; he was really Darth Sidious, greatest of the Sith Lords, and he used his political skills and Machiavellian cunning to bring down both the Republic and the Jedi. Palpatine ruled his Galactic Empire for decades, until he was betrayed by his apprentice, Darth Vader. Even this wasn’t enough to stop the Emperor, however, as he was resurrected by his followers - only to be defeated once again.