If he were to take his mask off, the Sith Lord would soon suffocate. So it's the most crucial part of his armor. He can only breathe without the need for his mask when he is in one of his meditation chambers seen in The Empire Strikes Back.
If he were to stand in open air without the help of his mask, he would stop breathing. And that's what happens at the end of Episode VI. Knowing he's going to die anyway, Darth Vader instructs Luke to remove his mask for him so he can look at his son with his own eyes — for the first, and the final, time.
One reason Darth Vader could speak with Anakin's voice was that he could talk without the mask. In Return of the Jedi, Darth Vader, redeemed as Anakin, was able to have a short conversation with Luke before dying on the second Death Star.
Why Can't Darth Vader Breathe Without His Mask? Dark Vader cannot breathe without his mask because his mask is connected to a life support system. His famous black armor suit covers this life-sustaining system.
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.
If Vader was able to access his full potential and immerse himself completely in the force, he would have no trouble overthrowing Palpatine... So for that reason, Vader's suit kept him in a constant state of weakness, but also brought his his full range of anger and pain.
Darth Vader's Suit Embeds Needles In His Skin
Unfortunately, these needles, which transmit neurological data throughout his body and allow him to control his limbs, also cause him constant pain. Between the never-ending itchiness and walking around with needles in his skin, it's no wonder he is so angry.
Purpose. Darth Vader's meditation chamber was a life support pod that allowed the Sith Lord to survive for extended periods without the helmet and mask of his suit. The injuries Vader sustained during his duel against Obi-Wan Kenobi on Mustafar normally made this impossible.
When Vader did sleep, he was awoken soon after by a disturbing series of visions, sounds and pain, most of which including Obi-Wan or Padme. It's entirely possible that he never really needed to sleep given the powers of his mechanical suit, however, his brain was still completely biological.
“You didn't kill Anakin Skywalker. I did.” Unmasking Anakin — As one Twitter user noted, Obi-Wan cuts open the left side of Darth Vader's helmet in Episode 6 of Obi-Wan Kenobi. Ahsoka, meanwhile, cuts open the right side of Vader's mask in the Star Wars Rebels Season 2 finale.
The sheer amount of light force energy needed for Force Heal could drain the Dark Lord's already fleeting energy reserves. Ergo, this is probably why he couldn't heal himself completely.
Bacta tanks are pretty magic, but they're not that magic. Simply put, Vader's wounds were far too serious for bacta to heal entirely. If bacta were able to do that, then neither Anakin nor Luke would have prosthetic arms.
Darth Vader was just 45 years old when he died. He was born on 41 BBY and died on 4 ABY during the Battle of Endor. Darth Vader basically killed himself when he betrayed Emperor Palpatine to save Luke Skywalker. This led to his life-support suit getting damaged by Palpatine's Force Lightning, leading to his death.
Padme's death fuels his rage, and his rage dictates his actions. It is only when he saw Luke, when he lost his anger for a second and felt his love for his son. That is at the center of all which is occurring in this comic.
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.
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. We have seen the abilities of top slicers like Tech in The Bad Batch and DJ in The Last Jedi.
Darth Vader feared his Master. The Sith lord who held his leash and the power to cause him unimaginable pain on a whim. The man who called him “My Old Friend” as a reminder that they were nothing of the sort.
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.
The confrontation results in a near-fatal outcome for Darth Vader who loses several limbs in the fight, and while he is incapacitated on the volcanic shore, he furthermore suffers inhalational injury and third degree burns.
Darth Vader's armor, also known as Darth Vader's suit, was a suit of armor worn by the cyborg Sith Lord Darth Vader. Designed with life support technology, the armor ensured Vader's survival following the lightsaber and burn injuries that he sustained in a duel with Jedi Master Obi-Wan Kenobi on Mustafar.
Weakness: Electricity
It took a single-minded desire to inflict pain upon another individual to transform the Force into such a destructive weapon. Darth Vader possessed the skill to use Force lightning, but the limitations of his suit prevented this.
So Palpatine may have been trying to accelerate Vader's dark side training by giving him more pain to fuel his power. And if it also prevented his apprentice from challenging him, all the better.