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.
Other Jedi practitioners of the dark side version of this power have been Relin Druur, Kyp Durron, Jaina Solo (in a black variant respectively), Kyle Katarn, Jacen Solo, Mara Jade Skywalker and Luke Skywalker. Luke Skywalker in particular was able to utilize a Emerald Lightning instantaneously kill his targets.
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.
In both cases, Dooku and Rey used Force lightning during painful or hatred-fueled moments, and while Maul certainly harbored anger throughout his story arc - particularly for Obi-Wan Kenobi - he never lost himself enough to spontaneously use Force lightning. But that doesn't mean he wasn't capable of doing so.
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.
Could Mace Windu Have Actually Survived? Let's Break it Down
Is Mace Windu considered a GREY Jedi?
The term “gray Jedi” in Star Wars is somewhat of a misnomer, considering that the definition refers to one who is practically non-Jedi. That being said, quite a few Jedi can be placed into this category. But Mace Windu identified as a Jedi despite his possible inclusion in the "gray" category.
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.
While he never showed the ability to use Force lightning before, it's appearance here helps communicate Kylo Ren's shift in his allegiance, and it's presently the only canon instance of Kylo using such an ability.
Mace Windu appears as a Force ghost in the alternate history comic Star Wars Infinities: The Empire Strikes Back in a vision to Darth Vader, though this may only be a mental vision in Vader's mind as opposed to an actual Force ghost.
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.
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.
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.
In canon, it has been speculated that Anakin could, but never learned how to before becoming Darth Vader. As Darth Vader, it's possible that he never did because lightning might be a technique where the electricity travels through your entire body, and Vader is mostly mechanical, so he would destroy his own body/limbs.
Using the Force, the Jedi and the Sith had the ability to deflect energy-based attacks like blaster bolts and Force lightning. A few even could block melee attacks, such as those performed with lightsabers.
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.
Darth Siberus, an ancient Sith Lord, had a unique Force lightning power that allowed her to drain the life-essence of others, a power not even possessed by Palpatine.
Mace Windu was a male Korun Human Jedi Master of legendary status who was the Master of the Order in the days leading up to the Battle of Geonosis, after which he gave the title to Grand Master Yoda.
In material that is now considered Legends, Qui-Gon is even described as a Gray Jedi. Additionally, the term has also been applied to Force-sensitives who aren't affiliated with the Light or Dark side of the Force. Quite literally, these Gray Jedi don't see things in black and white, or light versus dark.
Gray lightsabers are often associated with Jedi who do not fully follow the Jedi Code, but also do not fully embrace the Dark Side. These Jedi are often able to balance the light and dark sides of the Force and use their powers to serve the common good and are less likely to be influenced by the Dark Side.
