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.
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.
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.
Some Jedi do not even need a lightsaber to block Force lightning, with Master Yoda catching it in his hands. There is some evidence he absorbed the power of Force lightning into himself, using it to boost his own Force power.
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.
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.
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 ...
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.
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.
He was fully in control of the fight when he was blasting Luke. Instead of trying to outright kill his enemy, Palpatine just used enough force lightning to torture him for his entertainment. Not only that, but Luke didn't have to endure it for as long as the Sith Lord.
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.
Although instead of incapacitating like Plo Koon would, he has used it to instantaneous kill his targets although apparently has only used this against the Yuuzhan Vong. Legends Luke could use Force Lightning although he called it Electric Judgement, but it was Force Lightning all the same.
Given Rey's lineage as Palpatine's granddaughter, it is also reasonable to assume she is already better attuned to using Force Lightning than the average Force user, with Ben telling Rey that she has all of Palpatine's power within her at the beginning of The Rise of Skywalker.
Electric Judgment, also known as Emerald Lightning, was a Force power used by the Jedi to spray electric bolts of variable intensity from the hands and fingers.
Palpatine carried the lightsaber for a great deal of his life afterward, though he only rarely wielded it in combat, as his position as Emperor made battles with other Force-users few and far between, and he preferred to rely on his raw ability with the Force in any case.
Windu put his lightsaber between Palpatine and himself to block the lightning so it doesn't hit him. And yes, the other lightsaber users could just do what Mace Windu did.
Emperor Palpatine was able to send one storm over thousands of light years from Byss to Coruscant. Before being able to successfully create and control Force storms, a potential user had to be extremely proficient in the ways of the Force, including instinctive astrogation.
Typically, Humans had an average lifespan of 100 to 120 standard years. Those who were keenly atuned to the Force, an ubiquitous and binding power that suffused the whole Known Universe, could live up to 200.
