Force lightning ability was not restricted to dark-siders. Jedi and other light-siders who were strong of will and character could learn this power without falling to the dark side—but its use was viewed as inherently corrupting, and most Jedi Councils forbade its use.
Some have even speculated Sith can grow addicted to Force lightning. This naturally explains why Jedi do not generate Force lightning. Jedi seek to master their emotions rather than be mastered by them; Force lightning is therefore forbidden, as it is best understood as a spontaneous outpouring of hatred and rage.
Either way, while Vader can use most other Force abilities, Force Lightning needs to be channeled, and Vader's limbs are explicitly not connected to the Force. The Star Wars: Episode III - Revenge of the Sith Visual Dictionary confirms Darth Vader cannot use Force Lightning, and even suggests this is the reason why.
Yoda was incredibly powerful with the force (one of the top 5 force users of all time for sure) and he was able to block the lightning and push in back to Palpatine, which surprised the latter greatly. Force Lightning is a sith speciality, so it won't make sense for Yoda to teach Luke how to conjure one.
Originally Answered: Why wasn't Luke physically disfigured by Palpatine's force lightning in Return of the Jedi the way Palpatine was in Revenge of the Sith? Simple answer is often the correct one. Because Palpatine was in complete control. He wasn't actually trying to kill Luke yet.
Why Luke Skywalker Said Force Lightning Was the Most EVIL Force Ability Ever
Why did Palpatine age when using Force lightning?
Although, with the battle against Mace Windu in his office, Palpatine's Force-lightning was reflected back and scarred his face, making it wrinkled and appear far older than he already was.
Anakin Skywalker's Chosen One Potential Was Permanently Stunted. The Darth Vader comic book series reveals that, while the eponymous Sith Lord was indeed capable of using Force Lightning, the electricity could potentially destroy his life-sustaining suit.
Grandmaster Yoda himself was capable of summoning force lightning in the form of Emerald Lightning. Shaak Ti utilized this Force power. Her killer, Galen Marek was an extremely skilled user of this Force power, even after his conversion to the light side.
She and Kylo Ren were both trying to bring the transport to themselves with the Force, and in her anger, she accidentally unleashed lightning upon it, destroying the ship immediately.
Snoke was never a Sith, but he was nevertheless an extremely powerful unaffiliated dark side user. Unsurprisingly, Snoke was a talented practitioner of Force lightning, which he used to excruciatingly stun Kylo Ren when the latter lunged at him.
Mace Windu, with his lightsaber combat form Vaapad, could reflect the lightning back to its source with a "superconducting loop". It required tremendous effort on the reflector's part, however, as seen in Windu's battle with Palpatine; Windu was seemingly able to overcome Palpatine's lightning.
It became seen as a gateway to the dark side, with some choosing to practice it in secret. Remarkably, Mace Windu is only one of a few Form VII users who didn't fall to the dark side thanks to his refining Juyo into Vaapad.
Kylo demonstrably couldn't defeat Snoke directly, instead killing his master via deception. Kylo most likely never learned how to conjure Force lightning, which is considered an advanced skill for dark side users.
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.
Dooku first used Force lightning at a young age. According to the audiobook, Dooku: Jedi Lost, he was once abducted for a Dark Side ritual, conjuring lightning to kill his captors and escape. Dooku went on to become one of the greatest Jedi masters, but his ability to use lightning was seemingly a natural talent.
This could change over time as Cal succumbs further to the dark side's allure, so his Force Lightning could start off stunning his opponents before inflicting damage, then ultimately being used to kill.
Like his master, Darth Sidious, better known as Sheev Palpatine, Maul's main weakness was his overconfidence. In Luke Skywalker's confrontation with Palpatine during The Return of the Jedi, he tells the Emperor that his overconfidence is his weakness.
While many Star Wars fans would consider Yoda and Palpatine to be almost perfect antitheses of one another, it seems that they share a strange connection through Yoda's usage of Force Lightning in The Last Jedi that is eerily similar to something Palpatine did just a few years prior–and that connection goes much deeper ...
Summary. Some dark siders can conceal their appearance with the Force, hiding physical signs of corruption like yellow eyes and aged features. Palpatine's yellow Sith eyes may have been hidden through a dark side illusion, potentially masking his true form from the Jedi.
Ok so let's get into it Mace Windu survives, The fall but he has lost his weapon and is servilely wounded in now hostile territory. This is why I believe he would go into hiding for some time thoughout the early years of The Galactic Empire.
