The Sith Lord responsible for Anakin's fall Palpatine led Anakin Skywalker to the dark side and gave him the name of Darth Vader. The Emperor always knew the truth, and seems to have been the one who decided it should remain a closely guarded secret.
Did people in the empire know Palpatine was a Sith Lord?
It's pretty clear that the galaxy at large did NOT know Palpatine was a Sith during his reign, although a few high-ranking Imperials were either in on the secret or figured it out themselves.
The short answer is yes, without a doubt, Vader regretted becoming a cybernetic monstrosity. First, there's the constant pain and discomfort from his suit. Worse, however, is the psychological pain. Vader destroyed everything he had ever known for a chance to save Padme.
The added risk Darth Vader takes in allowing children to live in a situation where he could have killed them proves that he regrets killing Younglings and will avoid harming any more children for the rest of his days, though intense intimidation is a dark strategy to avoid repeating his Youngling massacre.
The Emperor always knew the truth, and seems to have been the one who decided it should remain a closely guarded secret. It's unknown whether he ever told Darth Vader's true identity to his closest advisers; some of these knew Palpatine's identity as a secret Sith, so may have known about Darth Vader as well.
Why the Emperor Wanted the Galaxy to Know Vader was SITH LORD - Star Wars Explained
Did Maul know Anakin was Vader?
Even in the old Star Wars canon, the two had a confrontation, as they met in the comic book Star Wars Tales #9, where Maul pieced together that Anakin was Vader.
Indeed he did. Dooku (aka Darth Tyrannus) knew his master's identity. At this point the Jedi thought Dooku was the Sith Master. The kidnapping was planned to reinforce public support for Palpatine while further confusing the Jedi about his true identity.
What we do know is he knew that the clone wars would happen, he says that in the clone wars. This means that he most probably knew about the clones and order 66. He doesn't know about anikin until about a week before order 66.
R2-D2 was present when Padmé gave birth to Leia and Luke, so he knew Luke was Anakin's son – but what he didn't know was that Anakin became Darth Vader. In addition to that, Anakin's fall was surely a painful event in R2-D2's life, one that he definitely wouldn't like to remember or even talk about.
At first, Ahsoka has no idea that Anakin Skywalker and Darth Vader are one and the same. She discovers the truth in Star Wars Rebels when she encounters the Sith Lord in a space battle. What she senses is so shocking to her that she passes out.
His backstory is explored in a flashback that occurs later in the game, which reveals that Cal was a Jedi Padawan training under Jedi Master Jaro Tapal during the Clone Wars, and that when Order 66 was issued, Tapal sacrificed himself to save Cal from their former clone troopers, leaving the latter guilt-ridden and ...
Yoda. Yoda's knowledge of Luke Skywalker's true parentage was also confirmed in Return of the Jedi. As with Obi-Wan, Yoda believed that Anakin's fall to the dark side made him unsalvageable, with the Darth Vader persona being his only identity following his ascension to Sith Lordship.
Yes, he sensed Order 66 and Anakin's turn to the dark side. In fact, it's not hard for a Jedi Master like Yoda to do so. Ahsoka Tano even felt the disturbance in the Force when she actually heard Anakin's words right when he turned to the dark side. And mind you, this was when she was on route back to…
It is mostly accepted that if Darth Sidious died, or was critically incapacitated, Darth Vader would succeed him as Emperor. This never came to pass though, as Vader died roughly 20 minutes after Sidious.
Maul most likely knew Sidious' double role as Palpatine and Sidious when he served as Palpatine's apprentice. He definitely knew about Palpatine's goal of creating a galactic empire ruled by the Sith. Maul knows that Sidious is the Emperor.
Palpatine saw Maul as a pawn and used him to his advantage, but never considered him a direct threat to his life. Palpatine didn't care about killing Maul for his failure, showing his carelessness and disregard for attachments ultimately led to his downfall.
Yep. Darth Maul didn't really say or show straight up that he "feared" Darth Vader, but he openly stated his belief that he could not defeat Darth Vader without the help of the Jedi, therefore on his own.
Despite seeing Vader as an idol, Kylo conveniently ignored his grandfather's redemption. He was well aware of what happened, and it's likely Luke himself who told Ben about the events of Star Wars: Return of the Jedi.
According to The Force Awakens: Rey's Story, Rey was reading Ren's mind when she talked about Vader. There's no particular indication that she knows who Darth Vader is or how powerful he was, other than what she's pulled out of Ren's thoughts.
Unfortunately, Rex and Vader never meet again though. Why didn't Palpatine feel afraid of showing his evil actions, behaviors and ways to Anakin and the Jedi anymore?
