Summary. Darth Vader displays an impressive new Force ability by creating limbs made from raw Force energy, saving himself from defeat. This power could have potentially saved him from his dismemberment and burns on Mustafar, but the current surges in the Force made it impossible at that time.
Bacta is by all means a miracle working chemical that allows for people to recover from a great many things, but Vader's injuries were far too severe for a bacta treatment to fix. It would have likely eased some of the pain, however there were far more pressing matters to attend to as I've already mentioned above.
After turning to the dark side of the Force, Skywalker severed Mace Windu's right hand to save Darth Sidious when Windu tried to kill the latter. Darth Vader lost his left arm and both legs when Obi-Wan Kenobi defeated him on Mustafar.
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.
As Han Solo, Chewbacca, and Leia were gathered in one location at the same time, Vader and his stormtroopers had the perfect opportunity to take them down. However, because he saw their dynamic as a source of weakness, he opted to spare them.
Why Vader Decided Not to Clone His Limbs - Star Wars Explained
Can Bacta regrow limbs?
While the bacta kept him alive and young far beyond his natural lifespan and healed the lightsaber wound his former colleague Santari Khri inflicted on him, it did not regenerate his missing arm, despite being immersed for 224 years.
Darth Vader also experimented with Force healing fueled by the dark side, in which meditation on anger and frustration at his life and circumstances allowed his lungs to function without the aid of his hyperbaric chamber or his life support suit.
In the main Star Wars timeline, of course, Darth Vader's attempts to resurrect Padmé on Mustafar were doomed to failure. But it's fascinating to speculate what would have happened had he been successful. In that scenario, Padmé Amidala's return from the dead would not have provided the solace Darth Vader sought.
After becoming Darth Vader, Anakin abandons his compassion for the clones and treats them as mere tools, showing no remorse or second thoughts when killing them.
Due to the strengthened Dark Side, Darth Vader, and Palpatine, Yoda has lost hope of being able to topple the Empire, calling it a "threat too big for me to defeat."
It was easy to believe that Darth Vader had kind intentions or a simple code of honor for the Sith, but his plans were much more strategic. Instead, Darth Vader wanted to keep Chewbacca alive because he wanted the Rebels to collectively suffer even more. He wanted them to be weak.
In the year 3 ABY, Fett saved Vader's life from an assassination attempt. In the aftermath of the battle, Vader revealed to Fett his true identity: Anakin Skywalker, and his past with the Jedi Order. It was here where Fett learned of the fate of Mace Windu, and how Vader had killed him.
I am not going that way not matter what” - that is what turns him. It is the end of Vader's journey to the dark side. “ And ”He takes the ounce of good still left in him and destroys the Emperor out of compassion for his son.
With that being said, if Palpatine did, indeed, use Force-healing to keep Vader alive, he didn't appear to have given enough life force for it to take a toll on him -- and being as close as Vader was to death, Palpatine would have required a lot of energy to keep him alive.
When Qui-Gon Jinn, Count Dooku, or countless Jedi during Order 66 perished, their bodies simply fell because they didn't consciously become one with the Force as Obi-Wan, Yoda, or Palpatine did. As Anakin died, he was guided into the Force by Obi-Wan.
He gave it to Luke Skywalker, who lost it when Darth Vader struck off his son's hand in Cloud City. The lightsaber then became part of Maz Kanata's collection of Jedi curios, where it called to the scavenger Rey.
