Skywalker was redeemed by his son, Luke, and fulfilled the prophecy of the Chosen One by destroying the Sith, but the redemption cost Skywalker his life. Upon death, Skywalker's body disappeared and his soul became one with the Force, leaving behind only the armor of Darth Vader.
In his final moments, Anakin comforted Luke, reminding his son that there had always been good in him—just as Luke had believed. Anakin then passed away, and his body disappeared into the light side of the Force.
Anakin, eager to prove himself, engaged Dooku in a lightsaber duel. In the midst of their duel, Dooku's skill with the lightsaber became evident. With a swift and calculated strike, Dooku severed Anakin's arm, leaving him wounded and incapacitated.
In the duel, Anakin lost both of his legs, his one remaining organic arm, and suffered (possibly up to) fourth-degree burns across what was left of his body that were severe enough to damage his internal organs.
He would have been in his 30s for most of Rebels. He was in his 40s during the original trilogy, 41 standard in 3277 (Rogue One, ANH), and 45 when he died in 3281.
Why Darth Vader Was Surprised When Obi-Wan Disappeared(Canon) - Explain Star Wars (BessY)
Why was Vader awake during surgery?
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.
In a Vanity Fair interview from 2005, George Lucas went deeper into why Anakin became much weaker as Vader. In the interview, he explained that because Anakin's limbs were severed and replaced by robotics, it was harder for him to use the Force than it was before his battle with Obi-Wan.
Mechno-arms were cybernetic replacements to hands and arms lost in a variety of situations, but more often than not by lightsaber blades. After Count Dooku severed the right arm of Anakin Skywalker in the opening battle of the Clone War, a mechno-arm was grafted to what was left.
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. A Sith's power level can also be determined when their "Sith eyes" are visible.
Notable Jedi like Yoda, Obi-Wan Kenobi, and Luke Skywalker are all examples of characters who faded from existence moments before their deaths. The reason these Jedi fade from existence rather than leave a body is due to teachings learned by Qui-Gon Jinn.
Like his Jedi masters before him, Luke Skywalker was also able to retain his consciousness as a Force spirit. Upon becoming one with the Force, the physical body of a Jedi vanished from existence either immediately or after a short period of time, leaving their clothes behind.
A dark side user's eyes would sometimes change color and burn yellow with a fiery red rim when rage and anger seethed inside them. Anakin Skywalker's eyes changed color in this way as he massacred the Executive Separatist Council on the planet Mustafar in 19 BBY, radiating anger and hate.
When Star Wars was originally conceived burns to over 50% of the body were typically fatal. If they get medical treatment fast, today people can survive burn injuries up to about 90% of their body. Next off, this usually refers to 3rd degree burns, not 4th, 5th, or 6th degree burns.
The canonical comic Star Wars: Darth Vader #7 confirms the younglings' deaths caused Anakin grief, self-loathing, hatred, and pain, fueling his descent even further into the Dark Side.
Did Anakin ever regret his actions? Anakin absolutely did regret many of his bad choices. After becoming Darth Vader, he pushed the regret down for awhile by dissociating himself from Anakin before the suit.
When tallying up the lightsaber losses, Obi-Wan Kenobi lost his blade a total of 12 times between the events in the prequel films and The Clone Wars. In contrast, Anakin lost his only eight times.
The other outliers in the Sith consist of Anakin Skywalker (27000 midi-chlorians), The Chosen one with the highest midi-chlorian count ever seen who was believed to be concieved through midi-chlorians, and Darth Vitaite (25000 midi-chlorians), a Sith Emperor that killed his step-father with a thought and defeated his ...
The highest known midi-chlorian count—over 20,000 per cell—belonged to the Jedi Anakin Skywalker, who was believed to have been conceived by the midi-chlorians.
So, in movies 1–6 as well as the Legends books, the reason he couldn't clone limbs or regenerate: No regeneration tech is available, they don't have that ability.
