He betrays his closest friend in hopes that, somehow, he can save others. Ultimately, the tragedy found in Anakin's willingness to rebrand himself as Darth Vader is that he betrayed himself. His forfeit of himself surrendered the capability of becoming great without having to concede to the Dark Side.
Arrogance
His arrogance leads him to make costly mistakes, like in his duel with Count Dooku in Attack of the Clones. He underestimates Dooku and charges at him before he and Obi-Wan can coordinate their attack. Dooku shocks Skywalker with Force lightning and throws him to the side, leaving him in a crumpled heap.
But the prequels, and especially Revenge of the Sith, are so special because of their depiction of Anakin Skywalker's downfall. He is known across the film industry as one of the greatest tragic heroes ever created.
He's Tragic
Darth Vader's story is one of tragedy, which makes him a sympathetic villain. He was once a promising Jedi Knight, but he was seduced by the dark side and turned to evil. This backstory adds depth and complexity to his character.
Darth Vader's Insecurities are His Biggest Weaknesses
In the end, virtually all who have made the attempt to use Vader's cybernetic nature against him have ended up dead or defeated. The elite few who have had the upper hand, even before his conversion to mechanical monstrosity, have done so by dominating him mentally.
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.
In Star Wars Canon, only Luke Skywalker can be acknowledged as the one who truly defeated Darth Vader.
He betrays his closest friend in hopes that, somehow, he can save others. Ultimately, the tragedy found in Anakin's willingness to rebrand himself as Darth Vader is that he betrayed himself. His forfeit of himself surrendered the capability of becoming great without having to concede to the Dark Side.
His armor could be hacked and controlled by a device. In a turn of events, Darth Vader's right limb holding his dangerous scarlet lightsaber was moving of its own accord toward his neck. This was a dangerous weakness indeed.
Once the heroic Jedi Knight named Anakin Skywalker, Darth Vader was seduced by the dark side of the Force. Forever scarred by his defeat on Mustafar, Vader was transformed into a cybernetically-enhanced Sith Lord.
Anakin does not have even the slightest bit of remorse. By the end, he feels nothing but anger. Although he feels regret for killing Padme, he still helps the evil Emperor. The film ends with Anakins standing side by side with the man on whose behalf he has committed all his crimes.
Darth Vader Has Claustrophobia
In addition to causing content pain and itchiness, the suit is so constricting that it causes him to suffer from claustrophobia. He can only find relief by meditating in specially-constructed pressurized chambers where he can temporarily take off his suit and survive.
Star Ewan McGregor was scared of Darth Vader when they met for the first time in Obi-Wan Kenobi.
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.
Darth Vader: Wiped Out The Younglings
As soon as Anakin Skywalker became Darth Vader, he already committed pure evil. He killed dozens of Jedi students, mere children, at the behest of his master.
Originally Answered: Are there any Jedi that can defeat Darth Vader in a 1v1 fight? Yes actually, Luke skywalker bested him and in his prime he can stomp vader.
Because his body had been severely burned on Mustafar, Darth Vader was thought to have lost much of his Force potential, although he nonetheless retained an incredibly high midi-chlorian count. As Darth Vader, Skywalker was believed to have had roughly eight-tenths of the strength of the Emperor.
Vader used his pain and anger to fuel his Dark Side powers, becoming one of the most powerful Sith ever and perhaps the most feared. He was the enforcer of the Empire, using his red lightsaber and black armor to strike fear into his enemies, becoming an instrument of terror to fight the Rebels.
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.
Yes, he did. He regretted it everyday. But he had no choice.
Vader, the only power who overrules him is papa Palpatine.
Because he was not an active member of the Jedi Order during Order 66, Infil'a escaped execution. 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.
We would have to give the victory to Darth Vader. While the two dark lords seem perfectly matched on their villainy and power, Darth Vader's lightsaber and ability to immediately use the force to choke Voldemort, without chanting any spell would end this showdown in seconds.