A challenge re: Galen Scaling
Galen Marek has far more feats to his name that I will not emphasize in this post, like one-shotting an army of thousands of droids and blowing apart a frigate. I think it would be a good idea to offer you the opportunity to show me the best environmental combat/short-term feats you can find for Revan or someone he scales off of, and let’s see who matches and mirrors better (we have other kinds of feats like powerscaling below). I think we both know where this will go – that Revan’s very best feats show up on like every page of The Force Unleashed’s novelization.
And Vader scales above both Galen and Starkiller, given that:
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[*] Most of these feats happen before Galen’s prime, when he wasn’t a remote match for his master.
[*] Even as of TFUII, pre-prime Vader is giving Starkiller a serious fight. He ragdolls him:
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You grab your sabers and attack, but Vader is too powerful. He tosses you away like a rag doll.
--The Force
Unleashed II: Prima Official Game Guide
And overpowers him in a Force battle:
https://static.comicvine.com/uploads/original/11115/111155790/5191688-7809924065-51913.gif
Given that Vader grows more powerful constantly (see later section), it seems clear that he can co-opt the general power of Starkiller and Galen Marek in this debate. And the fact of the matter is that Galen is taking out hundreds of opponents at the same time with singular uncharged Force pushes while Revan...isn’t.
Vader >> TCW Mace Windu > Revan scaling
Let’s talk about Mace Windu.
And, yes, a slightly different take on Kar Vastor scaling. A lot of posters have an aversion to Vastor scaling because the actual evidence has been a little mischaracterized - but when we delve more deeply into the matter, there really isn’t a case against it beyond personal incredulity.
First, we know Vader > Cronal:
Darth Vader, Dark Lord of the Sith, has instilled terror throughout the galaxy since the beginning of the Empire. His devotion to the Emperor and mastery of the dark side gives him more power than any single individual in the galaxy except for the Emperor himself.
--Shadows of the Empire: Prince Xizor vs Darth Vader Action Figure
And Cronal >= Kar Vastor:
And with the shadow nerve network of meltmassif lacing his body, [Kar Vastor] _had a connection to the fundamental power of the Dark that rivaled Cronal's own.
--Luke Skywalker and the Shadows of Mindor
From the above we can conclude that Vader > Vastor. This is independently supported by Nick’s assessment:
It didn't matter. There was no doubt in Nick's mind that, were Kar Vastor somehow to be pitted against Darth Vader, the feral Balawai renegade wouldn't stand a chance.
The Force was powerful in Vader; even the dim wattage of Nick's connection could feel that. It was far more powerful than it had been in Kar Vastor. It had pulsed from Vastor in waves of fury, blasted like an open furnace. In Vader, it was-contained. Pent.
--Coruscant Nights I: Jedi Twilight
Though Nick’s connection to the Force is limited, the whole point of the passage is to emphasize that Vader >> Kar is obvious in spite of that, not that Nick is delusional. To suggest that Nick is wrong in his assessment goes against both the most plausible in-universe explanation and the clear narrative intent (regardless of which you prioritize). Regardless, on its own it can be quibbled – with multiple lines of scaling and nothing contrary, Vader > Vastor becomes clear. It becomes even more clear when we happen to have Luke > Cronal scaling:
In the instant he thought the name, Cronal saw him: a shape of light, absolute, uncompromising, kneeling within the Election Center in the darkest heart of the Shadow Base, his hands solemnly interfolded with the massive paws of Kar Vastor. He had linked his shadow nerves to Vastor's, and through the intimate connection between Vastor and Cronal he had somehow stretched forth to touch the Shadow Lord himself.
In the Dark, Cronal saw Skywalker smile.
Thank you for joining me here. I was a little worried you might get away with that silly crown of yours.
This was impossible. This must be some hallucination, a twisted product of his Darksight run amok. He was in hyperspace! Hyperspace did not, could not, interact with realspace—I was with Ben Kenobi in hyperspace when he felt the destruction of Alderaan. No wall can contain the Force.
Shadows of Mindor
Full passage omitted for length but Luke basically telepathically dominates him. Luke six months after Endor obviously isn’t massively beyond Vader as a Force user, given that as of RotJ Vader could’ve still telekinetically dominated him:
Time seemed to slow. His head throbbed, pounding to the same rhythm as the beating of his heart. His face had gone cold, numb, and Luke realized distantly that Gethzerion’s spell had ripped open blood vessels in his brain, and he was about to die, one among hundreds of fatalities on this battlefield.
So this is how it would have been, if Vader had tried to kill me.
--The Courtship of Princess Leia
And it’s not merely telepathy:
He reached out with the Force and slammed shut the Falcon's hatch just as the Vastor body lurched to its feet and reached Luke in one lightning bound. Impossibly powerful hands seized Luke's shoulders as Vastor lifted him like a doll, and shook him and roared rage and bloodlust into his face, and there was nothing human left in Vastor's eyes. He sank his teeth into Luke's throat, and bit down.
[…]
He almost went face-first into the hull armor but managed to turn his crash into a clumsy somersault that left him flat on his back, dazed and gasping and staring up at the business end of his blaster. Which was in Luke's hand.
Luke said, "Didn't I tell you to go?"
While Han was still blankly mumbling, "Yow. Nice shooting. I think," the enormous Vastor-thing moaned like someone in terrible pain or fear or both. One huge hand slammed against Luke's chest, and for all Han could tell, it was like Vastor was the one in trouble and trying desperately to escape. An instant later, Vastor ripped his mouth free of Luke's neck-and his mouth was full of those black crystal hairs. The wound in Luke's neck wasn't bleeding, it was sprouting a thatch of that same blackly glistening fur that was writhing and twisting and growing like it was alive. Vastor gasped like a drowning man and yanked his other hand off Luke's arm, and before Han could manage even a faint guess as to what was actually going on, Vastor whirled, took four or five running steps for momentum, and made a great big flying leap right off the ship.
Luke tanks Vastor’s attack casually (Luke wasn’t trying to kill him).
So we have several lines of scaling to put Vader far above Vastor and you would have to resort to rather convoluted mental gymnastics to ignore them all.
It’s clear that Vastor >> Mace Windu in power:
Mace stood motionless except for the heaving of his chest. He knew already he could not match Vastor for raw power.
--Shatterpoint
Vastor was younger, stronger, faster, and immensely more powerful, and he wielded weapons that could not be harmed by the Jedi blade.
--Shatterpoint
Now Mace Windu loses the first fight to Vastor but wins the second, which hardly contradicts the ranking of their respective Force power given that Vastor is essentially untrained while Mace Windu is one of the most highly trained warriors of all time - and, as we’ll see, Mace doesn’t even win conventionally.
So, in power:
Vader >>> Kar Vastor >> (TCW) Mace Windu
Mace Windu, meanwhile, is Legends-canon above all Jedi to his time sans Yoda as of TPM:
Alongside Mace Windu, with whom he served on the Jedi Council, Yoda was the most respected and most powerful Master ever to have walked the corridors of the Jedi Temple.
--The Official Star Wars Fact File #11
Given that Revan is listed in the dramatis personae of the Revan novel as a Jedi Master, we know that:
Vader >>> Kar Vastor >> TCW Mace Windu > Revan
In power.
Continued below.