Hey! Nice that you made a new thread!
I do not want to sound rude, but I would again like to point out the plot holes, so you may remove them. 
First of all, lightning tribe was the last tribe to be created, not the first, and the only one made by Karzahni.
Karzahni was over time descending into madness, first, Ekimu and Makuta just isolated him, but when he really gone insane, they locked him in a prison. (I believe it was an island, but I may just reference my own Mahri Nui pitch unknowingly)
But it is certain that Karzahni was not free to roam around, though maybe he could be strong enough to still create something, such as the monster terrorizing Naho.
All three brothers made the island, then the matoran and rahi, then the elemental gods and after that Ekimu gave them sentience, because he believed it was a gift.
This greatly upset Makuta, who saw it as cruel and wrong. What I love about this, is that Makuta is not a villian here, he has a point.
I will put here his point of view, as explained by one of the TTV members, I believe it was Kahi. “Imagine you played Call of Duty. And then imagine that all of the people in there are real. That you are actually killing real people.”
Well, back to the plot holes.
After the argue between Makuta and Ekimu, they agree to leave the Matorans alone and don’t do anything. But then the tribe of lightning is discovered. Makuta is enraged that Ekimu broke their deal, the two brothers begin to fight.
Their fight shakes and almost destroys the island, so the Elemental Lords decide to overthrow their creators and restore peace.
The tribe of lightning was actually made by Karzahni, but I do not know if this would be revealed, or when.
One more thing: Maybe you could change your title a bit to include the Skakdi and the Vortixx, this may alude more attention from both community and TTV.
_
I don’t see anything else contradicting the canon, so you’re doing nice so far. Please, be ready to edit or even really change your pitch, I expirienced this myself. Community’s suggestions are often much better than what you would think about!
Also, I love your drawings! You should definitely continue and draw more!