Fix your lore!

whom? Whom was it?

http://starwars.wikia.com/wiki/Force...ng#Use_by_Jedi

Galen Marek was an extremely skilled user of this Force power, even after his conversion to the light side, rivaling Darth Sidious.

I hate to break it to you but not everyone cares. Me personally, I really don't care if Revan was male, female, gungan, or hutt (for example). IT DOESN"T MATTER!

http://starwars.wikia.com/wiki/Force...ng#Use_by_Jedi

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 Jedi nonetheless refused to dismiss the natural power of this ability. During the Great Sith War, Jedi Master Lian Dray used Force lightning against the Sith apprentice Sindra. Revan, Meetra Surik, Jolee Bindo, Bastila Shan, and Vrook Lamar were amongst its users during the Mandalorian Wars, the Jedi Civil War and the First Jedi Purge. Plo Koon used this ability (which he called Electric Judgment) to subdue a criminal named Pommel, who had taken a hostage. Koon used Force lightning to knock Pommel out, yet claimed to have no plans to experiment with it in the future. Quinlan Vos could also employ this power effectively, and used it against the Anzat Jedi Volfe Karkko. Darrus Jeht also used Force lightning against the Dark Jedi Asajj Ventress.

Galen Marek was an extremely skilled user of this Force power, even after his conversion to the light side, rivaling Darth Sidious. He could kill foes with a single blast and was able to hit many adversaries at the same time. He was also able to deflect Force lightning with his lightsaber or even with his bare hands such as during the Battle on Death Star I. He could also charge objects and people with lightning and use them as improvised grenades, and to create a shield of lightning around his body to protect himself. Marek's clone was even more proficient, being able to set stormtrooper armor on fire with the power.

Some members of the New Jedi Order such as Kyle Katarn and Jaden Korr also used Force lightning (colloquially known as "Emerald Lightning"), but it remained very controversial. Other Jedi practitioners of this power have been Relin Druur, Kyp Durron, Jaina Solo (in a black variant respectively), Jacen Solo, Mara Jade Skywalker and Luke Skywalker. Skywalker in particular was able to utilize a green variant that possessed the ability to instantaneously kill his targets without succumbing to the dark side. However, he was only known to have utilized this deadly variant during his engagement with the Slayers during the Recapture of Coruscant.

Cade Skywalker was able to use Force lighting in a unique way. Utilizing his ability to see Shatterpoints in people and objects around him, he could use lightning to heal people, bringing them back from the very edge of death, or to kill them.

Galen Marek is considered Canon btw...

Edit: At least last I saw The Force Unleashed was considered as much. May have changed... thought it would be because Lucas himself was in on the story writing. Looks like it may have been classified as Legends.

THIS is what I'm trying to rectify and you know this already from page what was it 4? to here now?

And he was grey and or Dark. meaning he wasn't on the true jedi path he was on a rogue path a freelance force user path, not a jedi. or he was a Sith apprentice

The only one trying to ignore Light Sith and pretend that they don't exist is you, my friend. No matter how many times you try to trot out the "no true Sith" blather, it doesn't cease it from being your own personal head-canon.

Okay your head canon crap is getting redundant I'm reporting you for trolling.

its canon that all sith are darkside. based on what IS considered canon anyway

He was a Sith Apprentice who was redeemed to the Light.

He was effectively, at that point, a Jedi with dark side abilities. But really, the issue is that the structures and rules of the Orders are irrelevant. Abilities were based on the connection between the force user and the respective halves of the force. As for whether the Jedi order would "approve" of force lighting? Well... we don't really see that in this game so who cares?