It has been revealed in a new Star Wars comic the reason why Darth Vader was never able to overthrow the Emperor. Although recent comics have given the Sith many reasons to betray his master, there is now an explanation why his plans never worked out.
Despite Vader's seeming loyalty to the Emperor, Palpatine wanted to replace his servant with a new apprentice, while Vader plotted to overthrow the Emperor so he could rule the galaxy with his son. In the end, Luke surrendered himself to Vader on the forest moon of Endor.
Star Wars Legends, specifically the novel Dark Lord: The Rise of Darth Vader, explained that even though Vader was capable of killing the Emperor, he wasn't in good psychological condition to do so.
During the Imperial Era, sometime after the Duel on Cloud City, the Sith Lord Darth Vader undertook a mission to the planet Exegol in the galaxy's Unknown Regions to confront his Sith Master, the Galactic Emperor and Dark Lord of the Sith Darth Sidious, also known as Sheev Palpatine, and uncover his secrets.
Emperor Palpatine should have known Darth Vader would betray him in Return of the Jedi, but he was blinded by his arrogance and ignorance. Palpatine couldn't predict Darth Vader's betrayal in Return of the Jedi for one simple, yet very powerful reason.
He often refers to Vader as a tool that can be discarded when he is no longer of any use, and yet still Vader obeys. Despite wanting Vader to obey, Palpatine still sees his apprentice as pathetic and someone who could never surpass him.
It was for that love that Vader killed Palpatine, but according to Darth Sidious himself, it was a "pathetic display" and "all for nothing," because in the end, Darth Vader sacrificed his own life yet "the Sith would return."
Giving in to his feelings, Anakin cuts off Mace Windu's hand, giving Palpatine the opportunity to kill him. Anakin regrets this almost instantly, but the thought of Padme was stronger than his remorse This is the moment Anakin officially became Darth Vader and led to serious issues in the Skywalker Saga.
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 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.
Star Wars Confirms Darth Vader Was ALWAYS Obsolete, Thanks to Palpatine. While Emperor Palpatine seemingly did everything in his power to keep Anakin alive, he still made sure to nerf a major part of Darth Vader.
No, Darth Sidious did not respect Darth Vader. Not likely he feared him but saw his value as a puppet. What differentiates Darth Sidious from Darth Vader? Mainly style.
Palpatine proceeds to almost entirely exterminate the Jedi through Order 66 and manipulate Jedi Knight Anakin Skywalker into becoming his new apprentice, Darth Vader. He transforms the Galactic Republic into the Empire and declares himself Emperor, using Machiavellian manipulation to invoke martial law.
The following factors led to Vader's success: Vader caught him off guard. Palpatine didn't have enough time to get over the shock of his betrayal to think strategicially, so he just tried ramping up the lightning. Palpatine was blasting Vader with (presumably) Force lightning of the greatest intensity.
Vader is not afraid of Palpatine but he is most definitely wary of him. He knows that Palpatine can kill him in seconds if he wanted to. But Vader isn't afraid per se. He hates Palpatine and he knows his master's power.
Similar to how Sidious replaced Dooku, he soon began planning on replacing Vader, as well. He was always seeking a more powerful successor and was especially intrigued by the powerful Skywalker bloodline. He soon placed his sights on Luke Skywalker (Mark Hamill), hoping to kill Anakin and replace him with his son.
It's not shown, but it is clearly insinuated that Anakin killed the younglings. This is confirmed later in the movie when Obi-Wan informs Padme that Anakin killed them. Both are torn apart with hurt and confusion, trying to make sense of something so terrible. How could Anakin do such a thing?
As we know, Vader was killing children before he even got his suit on, but those were Jedi younglings and so future potential threats. Vader doesn't kill right and left just to be “evil.” A random kid hugging him would presumably be brushed rather brusquely aside, but that would be all.
The maverick Jedi Master Qui-Gon Jinn comes before the Jedi High Council, which Windu is a member of, and offers to train Anakin Skywalker, believing that the boy is the Chosen One of Jedi prophecy. Windu and the other Council members decline, deeming Anakin too old and full of fear.
If he had not burned, Vader could've been stronger, faster, more agile, and continue to perfect his original lightsaber fighting style instead of having to relearn how to fight with a modified Djem So. He would also be able to use Force lightning if he was never burned.
A Sith Lord with the ability to cheat death and create life, Plagueis is the mentor of Sheev Palpatine / Darth Sidious, who, in accordance to the Sith's Rule of Two, eventually betrays Plagueis by murdering him in his sleep, taking his place as Sith Master.
No. Anakin's sacrifice was to save his son by love. And that's what he did ! He killed Palpatine not by revenge, but simply to save Luke and indirectly Leia.
Vader relies on the complex life support system of his suit to survive and it happens to be very vulnerable to electrical discharges. So, if Vader ever had unleashed Force lightning, there's a good chance it would've caused his suit to short circuit, thus, killing him.