Each took some serious blows too; Obi-Wan was buried under rubble, while the Jedi Master eventually struck back with an onslaught of rocks, including one that pierces Vader's mask and – potentially – causes the scarring that sticks with him decades later.
Three years prior to the Battle of Yavin, Vader engaged in a duel against his former apprentice, Ahsoka Tano, inside the Malachor Sith temple. During the duel, Vader's helmet suffered considerable damage, disabling his vocal modulator and exposing his right eye.
That is, until he duelled with Rey in a Force-connected lightsaber battle in The Rise of Skywalker, which saw the pair, who together make up a Force dyad, inadvertently destroy Vader's helmet.
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.
Always a canny foe, Ventress baited Anakin by threatening to kill Padme Amidala, before striking him across the face. The scar became another symbol of Anakin's journey to the dark side when he punishes Ventress by binding her in cables and flinging her from the top of a skyscraper.
Star Wars: The Visual Encyclopedia says that as "windows to the soul, eyes reflect the emotions harnessed by the Sith. When rage and anger seethe inside a dark side user, their eyes may burn yellow with a fiery-red rim." What that means is a Sith's emotions will be shown through their eyes.
Real in universe answer: not every force user can use every force power. Not every Sith could use force lightning, not every Jedi could use force run, etc. Force healing just wasn't an ability everyone could use and it doesn't look like the Jedi even taught it during the republic era.
Despite how integrated the suit appeared to be with regard to Vader's cybernetics, virtually all of the external components of the suit could be removed in their entirety, as Vader was known to routinely remove both the suit and his prosthetic limbs during maintenance sessions.
While the suit was necessary to save Vader's life after Mustafar, Lucas makes it clear that, in his mind, after a brief period, he could have survived without it. Of course, he wouldn't be the physical presence he is in the suit, which doesn't work for someone so enthralled and held captive by the Dark Side.
"The Steadfast Soldier" may be telling the story of how Vader's helmet was recovered by the Imperial Remnant. It would later be passed down to Kylo Ren, perhaps as a gift from Supreme Leader Snoke to sink his claws into his new apprentice.
This occurred because Vader was not Luke's enemy in the Cave of Evil. Instead, Luke was fighting himself and his own fears, which Luke discovered when he saw his own face in Vader's helmet.
After confronting Darth Sidious on Exegol, Ren decided that the time had come to rebuild his helmet. Following the assassination of Snoke, the self-appointed Supreme Leader Kylo Ren retrieved the shattered remnants of his helmet from the wreckage of the Supremacy.
During the battle, Anakin, who had been known as the Sith Lord Darth Vader, was redeemed by Luke and brought balance to the Force. However, the redemption cost Anakin his life, having been mortally wounded by the Emperor, Darth Sidious, while killing his former Master.
Darth Vader's final words were “if you will not turn to the dark side, then perhaps she will”. Anakin Skywalker's final words were: “You were right. You were right about me. Tell your sister…you were right”.
The mask also represents the villain's fragility and, of course, his weaknesses, and that's why Darth Vader taking the mask off to Luke at the end of Return of the Jedi is so significant. He's showing his son who he really is, or the person he used to be: Anakin Skywalker.
Darth Vader weighed 120kg (264 lbs), and most of that weight is because of the armor's steel and obsidian components. This means Darth Vader is unable to move at all at speed, and he needs the assistance of cybernetics.
But while it was out of character for a traditional Sith Lord, Vader's past as Anakin Skywalker showed that his compassion towards the soldiers he led was a major part of his character.
As an addendum to what Infantry said: Sidious didn't ask to the med droids to put anesthesia in Anakin on purpose. He wanted him awake in order to feel the pain during the whole procedure, since pain is part of the Sith philosophy of life. Vader being born out of pain was not only metaphorical, but also literal.
While there were certainly less bloody ways for the shift in power to occur, Anakin's downfall expedited the process. Had he never become Darth Vader, the Republic may have gone on to become more and more corrupt until, over time, it became just as heinous as the Empire itself.
He knew that her death is inevitable, but he wanted to hold on to her, he wanted to stop her from dying, to stop the suns from setting, to stop change, to alter the way of the universe. The problem Anakin Skywalker seeks help for is: “I had premonitions, I know someone I love is going to die.
