Weakness: Electricity A lot of the systems that were keeping Darth Vader alive were maintained by electricity, which is why Force lightning was so destructive towards him.
Darth Vader can not use force lighting, because of his severed arms. Robotic hands can't summon the force lighting. However Darth Vader can still use other forms of the force, such as force choke.
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.
Originally Answered: Could Darth Vader block force lightning like Yoda could? No he'd be able to block it with his lightsaber like Mace Windu or Obi Wan Kenobi, but not with a palm force ability like Yoda, at least based on what we know.
A Jedi and Sith could deflect the lightning with a lightsaber, such as when Obi-Wan Kenobi blocked Dooku's lightning with his saber; a powerful Jedi Master such as Yoda was capable of deflecting the attack using Force deflection but only for a short while and with immense effort.
He also attempted the technique on Obi-Wan Kenobi, who was able to block it with his lightsaber, and Master Yoda, who managed to reflect and dispel the energy with his bare hands.
Gray Jedi commonly demonstrated their skills with both Light and Dark side Force capabilities. For example, the capacity to construct a lightsaber from scratch, along with unique Force talents such as Force lightning.
The armor had ten protective layers, each made of very strong alloy that could protect Vader from some explosions and weapons. Vader had four artificial limbs as a result of his injuries on Mustafar and at the hand of Dooku on Geonosis. The apparatus of Vader's mask was designed to support his breathing.
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.
Aside from his sensitivity to the Force, the Jedi are keen to note the overpowering sense of fear that controls him. The lack of coping or direction given to him by the Jedi Order allowed Anakin to become more susceptible to the threats of allowing his fear to win.
1 Luke Skywalker
Having faced his father once before, Luke was familiar with his tactics and used the force to gain an upper-hand. In Star Wars Canon, only Luke Skywalker can be acknowledged as the one who truly defeated Darth Vader.
1 Darth Sidious
As well as being a gifted bladesman Sidious' connection to the Dark Side is extremely powerful, granting Sidious the ability to conduct force lightning.
Despite being equally as strong in the Force, one innately Sith ability that Jedi in the Star Wars franchise do not wield is Force lightning. First introduced when Darth Sidious (Emperor Palpatine) electrocuted Luke Skywalker in Star Wars: Return of the Jedi, Force lightning is a powerful weapon for Sith.
Darth Vader physically cannot use Force Lightning. He has access to Force Lightning-esque abilities, such as Kinetite, but that is not the same thing as true Force Lightning generated within the spirit.
Darth Vader's Suit Embeds Needles In His Skin
Inside his suit and mask, Vader has a series of 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.
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.
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.
Green is considered the second most common lightsaber, behind blue.
The shading purple speaks to moral uncertainty, reconstruction, and recovery. Therefore, the individuals that used a purple lightsaber generally shared an affinity with both the Light and Dark sides of the Force.
Jedi Battlemaster Cin Drallig and Grand Master Yoda had knowledge and mastery of all seven forms, including Juyo, befitting Drallig's role as lightsaber combat instructor at the Jedi Temple and Yoda's reputation of having mastered all forms of lightsaber combat as did Anoon Bondara, another lightsaber instructor.
Darth Rayze is the only confirmed user of Red Lightning. Darth Validorn also attempted to use this power on Darth Rayze, though it is unknown how he learned to do so. It has been speculated that Red Lightning is just Force Lightning whose Lightnings temperature is so highly intense that it is red from heat.
Yoda's Lightsaber Form Hints He Was Vulnerable To The Dark Side - IMDb. With the various forms of lightsaber combat in the Star Wars universe, the form that Master Yoda employs suggests of a possible weakness to the dark side's sway.