No force lightning dark side?

[Rockets]

wtf were they thinking?

[EricHVela]

I doubt that this Jedi trilogy is going to tap Legends without official support.

Legends also can't seem to decide what to call it. Fingertip Lightning. Electric Judgment. Emerald Lightning. Then, you have the Potentium heresy issue that makes its use even more questionable given the negative influence that was having on Jedi.

Could possibly be best left in Legends. Let's assume we're discussing Canon as known so far.

[Syrup-free pawjobs]

In Disney canon Dooku used lighting before he left the order, and Plo Koons lightning is blue instead of yellow. It is mentioned by Plo that ancient Jedi used this ability but its now regarded as a dark side power. There is also mentions in the high republic books.

[Kalle_Demos]

Emerald Justice is the Jedi equivalent to Sith Lightning. As to why Cal doesn't have the ability? They are both regarded as high level skills and he simply hasn't achieved that level of skill and power yet. If he would even ever choose to use them at all. Many high level Jedi that perhaps could use Emerald Justice, such as Plo koon who did, simply chose not to because it is very aggressive.