As powerful as Darth Sidious may have been, it's easy to forget he actually seemed afraid of Master
So even though Jocasta Nu was deemed nothing more than a mere librarian, her acts of preservation would actually go on to aid a brand new generation of Jedi for years to come, making her, truly, a formidable adversary and worthy of Palpatine's fear.
Most viewers have forgotten that Palpatine seems to have been afraid of Yoda in Star Wars: Episode III - Revenge of the Sith - and even tried to flee from their duel. Yoda and Obi-Wan Kenobi were among the few Jedi to survive Order 66.
The Fermata Cage Truly Scares Palpatine
In Star Wars lore, the Fermata Cage is indeed an ancient Sith device that currently holds another Sith Lord. Palpatine sees this Sith as his rival and the only true threat to his galactic empire.
In the film, we learned that Rey was a Palpatine, and her father was a clone of the infamous Sith Lord. However, it did raise the question of why would Palpatine let one of his clones escape especially since he was later revealed to be a failed clone.
Due to his abandonment during battle, Hock hated the Jedi. During the Clone Wars, he had considered them to be fearless warriors, but believed others could be fearless even without a lightsaber, and that even Jedi could make mistakes.
After learning of his plans through interrogation, Clone Captain CT-7567 "Rex" resolved to execute Krell for committing treason, though ultimately it was trooper CT-6922 "Dogma" who shot the fallen Jedi, resulting in Krell's death.
Jedi Master Yoda is the most powerful of them all. This should come as no surprise, as he was the head of the Jedi Order in the prequels and was revered for his abilities during the original trilogy. Yoda's power is unmatched and was a real threat to Darth Vader and the Imperials.
Even after his brutal scorching in the fires of Mustafar, sand remained the only natural phenomenon that Vader feared. To him, sand was a reminder that he'd failed to save his mother or Padme from death.
As powerful as Darth Sidious may have been, it's easy to forget he actually seemed afraid of Master Yoda. As seen in Revenge of the Sith, Palpatine initially thought he could deal with the aged Jedi Master - and then, when Yoda proved able to counter the Sith Lord's Force lightning, he fled.
Thus, while Qui-Gon was less powerful than Yoda, Palpatine feared him more.
It's implied that this isn't feigning and Palpatine is actually fighting to win. In the book its implied that he allows Mace to move him and make certain moves, however this is a not uncommon dueling tactic, waiting for openings and surprising an opponent.
If Rey struck him down, Palpatine's spirit would pass into her, allowing the Sith to be reborn. Rey resisted him with the help of Ben, who'd returned to the light. But their defiance gave Sidious a new opportunity – he would drain the energy of their Force dyad to restore his own body, then rule alone.
Jedi Masters Mace Windu, Kit Fisto, Saesee Tiin, and Agen Kolar confronted Chancellor Palpatine upon learning of his secret identity as a Sith Lord.
In Luke Skywalker's confrontation with Palpatine during The Return of the Jedi, he tells the Emperor that his overconfidence is his weakness. That turns out to be true as Palpatine takes too long trying to kill the young Jedi, which gives Darth Vader...
Amedda was one of the few beings in the galaxy who knew Palpatine's secrets, most notably his true identity as a Sith Lord.
In Star Wars Legends and Canon, Galen Marek (Starkiller) is the only Jedi (other than Obi-Wan Kenobi) to put a beat down on Darth Vader/Anakin Skywalker. Galen was secretly trained as a Sith Lord apprentice to Vader, but returned to the light side and the Jedi.
In the Star Wars Universe, it's hard to deny Darth Vader's greatest enemy was the Jedi Order. Sure, he had enemies such as Qi'ra, the Crimson Dawn and Doctor Aphra. But few came close to truly defeating him, other than Obi-Wan Kenobi and in time, his son, Luke Skywalker.
Some time later, he faced the Sith Lord Darth Vader. Infil'a put up a fierce fight against Vader, almost killing him by throwing the already damaged Sith Lord off of a cliff. Despite severe damage to his suit, Vader survived the fall, and repaired himself with parts from Infil'a's droid, Arex.
1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
Yoda. Yoda was a wise, experienced, and powerful Grand Master of the Jedi of an unknown species and the oldest known prophet in existence (having lived at least 900 years), considered the wisest and most powerful Jedi Master within the Star Wars universe.
Some clones disobeyed the infamous order than decimated the Jedi order, and refused to execute it. SOME of these Clones include; Captain Rex: Captain Rex, as most know removed his chip that would later be the way that Palpatine would execute order 66. Wolffe: As with Captain Rex Wolffe removed his bio chip.
In the Star Wars franchise, Order 66 is a directive ingrained in every clone trooper to eliminate every Jedi in sight, but some clones managed to disobey the order when it was executed during Revenge of the Sith.
Venku Skirata was born on the planet Mandalore, the son of the Jedi Etain Tur-Mukan and clone commando Darman Skirata. The child's father, Darman, did not know that Etain was pregnant, and was unaware he had a son until a year after the child's birth.