And the Chosen One had the potential to be the greatest being ever to exist. Born from the Force itself, Anakin could have been even more powerful than Luke (though not by much). He ended up being 80% of Sidious' power. And Sidious is more powerful than any before him by leaps and bounds. This automatically makes Vader greater than these other combatants.
Force Potential isn't everything, Boba Fett fought Darth Vader on multiple occasions even to a draw at times, and Fett wasn't force sensitive.
Vader is not weak to lightning. Not the actual lightning. It is the force behind the lightning that affects Vader. The lightning that Starkiller used against Vader was amplified by Kamino's lightning towers. And Vader simply fell to one knee. Had Vader been weak to lightning, he would have died. Sidious' lightning killed Vader because it is the most powerful lightning ever. This is the lightning that could tear apart fleets of ships. So the lightning of these guys doesn't really help them.
Seriously if Sidious' lighting was that powerful why did he need a Death Star? He could fire force lightning in a space suit if that were the case...
Fact of the matter is you're just looking at video game mechanics, Vader's insulation had been damaged allowing Starkiller to force lightning Vader into submission according to the Novel, generally the Novel trumps the videogame.
Yes, compared to these guys, Vader is slow. But his raw physical strength could overwhelm any opponent.
He'd probably be evenly matched in strength with Bane.
I highly doubt Revan could absorb one Kun's force blasts. Blasts that can destroy durasteel walls.
I don't think any of these guys are push overs, I know there are a lot of haters out there, but Revan accomplished some pretty impressive feats, he isn't exactly a slouch with a lightsaber nor is he a slouch when it comes to the force.
I'm sorry to say, but Revan doesn't have a chance going up against any of these guys. Exar Kun has better saber skills and Force power. Bane destroys Revan with his pure strength and Force power. Vader is the better duelist and has far more power at his command than Revan. Even his tactical skills won't help much here.
My analysis had nothing to do with raw potential whom is arguably the strongest, it boils down to simple logic. The first person to attack is most likely the first one to die, because he opens himself up to attack from the other two.
Vader was able to take on multiple Jedi at once because they had to avoid hitting each other, and Vader was able to use that, cause he could strike with impunity.
This fight is a four way slug fest, there aren't any allies, so in being the first to attack and/or first engaged means you're all tied up fighting with one person and the other two people can and will attack with impunity.
Revan is most likely to survive it because he's the most patient, the least likely to be the first one to attack, and probably wouldn't waste time with taunts either, so he's the least likely to be the one that is first attacked, and he's the least likely to be the first attacker.
Bane may know patience, but Exar Kun is bound to get on Bane's nerves. So the initial combatants are probably going to be Bane vs Kun. Bane's resistance to lightsabers means that only Revan or Exar Kun can take him down. The others will figure out Bane's resistance fairly quickly, Vader would probably go in to take down Exar Kun. Revan will probably force lighting Bane along with Vader for good measure.