Kol has done stuff we've never seen before, like killing a Sith by reflecting its own lightning, and in his last stand on Ossus he took out several Sith and even more troopers. And given that he's a Skywalker in his forties, about the same age as NJO Luke, the only people/teams there that I think could maybe defeat him would be Krayt/Nihl and Revan/Malak, the latter having the best chance. All the rest are just fodder.
I forgot what happened in issue 1. Wasn't he killed by force lightning from Nihl? I wonder if that means his force lightning is near the level of Sidious.
He was basically slaughtering every Sith and stormtrooper present, and had already wounded Nihl (he was thought dead by many) until the guy fried him from behind with lightning. That doesn't put Nihl on Sidious' level - Dooku, Malak, and many, many others have accomplished similar feats, and it's not like Kol was prepared for the attack.
From what we've seen, these lower level Sith are weaklings, ergo there's no reason to assume she is any different.
And simply because she died doesn't mean it's "stuff we've never seen before". Mace Windu ring a bell? Except in his case, he was actually dealing with the supposed most powerful Sith ever, not some tool of the Sith.
It's hardly anything special (if AotC Obi-Wan can absorb lightning, I'd imagine it wouldn't take an immense amount of strength more to reflect it, especially if its potency is low).
Honestly, I'm not trying to take anything away from Kol, as it's quite a display of power, but this feat isn't as impressive as you'd like to make it out to be. He only killed seven of these Sith minions from what we know, and given their obvious lack of prowess, it's hardly anything that would put him even on par with someone like Count Dooku.
What does his age being nigh parallel to Luke's have to do with anything, Faunus? Kol is not Luke. Kol's Force potential is not equal to Luke's and they have nothing to do with each other when in comes to power.
We have no idea how deluded the Skywalker bloodline has become and simply being a "Skywalker" doesn't grant one immense power in the Force. At least, it doesn't automatically mean you are going to be one of the most powerful beings in the history of the galaxy (which is exactly what you're implying).
Considering both Count Dooku could take down Kol and his ancestor, Anakin, could also defeat him, I don't know how you drew such a ridiculous conclusion.
Your proof for naming Kol as some type of demigod is that he defeated some weak Sith warriors and he's a Skywalker in his 40's (which means little). If he were anywhere as strong as NJO Luke, he would've decimated every single one of his opposition on Ossus given what we've seen his son and Shado Vao do to some of them.
If Kol was a "somewhat watered-down version of JA/NJO Luke", then he likely wouldn't. But since Kol isn't, I see no reason as to why he shouldn't be able to handle him.
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"The ability to speak does not make you intelligent." - Sagacious Jedi Master Qui-Gon Jinn.