Anakin picked his way across the room, careful not to step on any of the bodies strewn across the floor. They'd all deserved what they got, but now he had to think. Despite clearing the bunker of life, the Separatists were still out there. Nothing was finished, nothing settled. He would have to follow them, taking out the leadership wherever they had hidden themselves. A flashing indicator caught his eye-- the proximity alarm had been triggered, probably by his own ship's landing. He gave it no more attention and sat down to figure out where the real Separatist leaders had gone.
Obi-Wan Kenobi released the controls of his starfighter as the autopilot received instructions from the landing platform. Weary with grief, he tried to center himself for the coming engagement. Master Yoda wasn't having these problems, he was sure. Yoda was the perfect Jedi-- no attachments or doubts at all. Sure, his pain at losing his companions and students had hit him. There was no mistaking the pain in the diminutive Jedi's eyes. But as soon as the Shadow's life had been extinguished, the planning to kill Anakin, no, kill Vader had begun. With cool competence, the Grand Master had delved into the security systems of the battered office to trace the Sith's final victim. Even Master Windu's cloak by the window merited no more than a sigh, seeming exasperation at 60 years of wasted training. Yoda's example was quickly becoming impossible to follow; Kenobi's relationship to Anakin was something he'd come to cherish as much as his connection to the Force.
The two starcraft containing the entirety of the Jedi Order touched down a stone's throw away from an ocean of molten rock. The birth pangs of a planet had been the locus of the war's throes of death. Taking a last deep breath of the controlled atmosphere of his starfighter, Kenobi reluctantly emerged into the blistering heat. Yoda was already waddling through the door, relying on his walking stick to help sustain the weight of the hundreds of years and thousands of deaths on his back.
"Easy to find, Vader will be. Amidst his handiwork he is."
"Master, you are sure that Anakin cannot be redeemed? We could apprehend him, rescue him. He is--"
"Discussed this we have. Exposed, Vader's identity must not be. Destroy hope in the Jedi it would."
"But--"
"Master Kenobi. Master Yoda. So you are the ones they picked. You know this is a suicide mission, right? No real Jedi could stand against me, so what chance do you have?" The cocky confidence in the voice was unmistakable. It was Anakin!
"Anakin! You have to listen to me!"
"You have no right to use that name! You of all people!" His voice quivered with rage, and then changed. "And here I was all set to let you leave alive." Something about him had been perverted. His voice, formerly as earnest as ever during the War, had acquired a slightly sneering condescension. His back was straight, as though in defiance of their judgment. His lightsaber's hilt, suddenly bleeding blue fire, was flecked with blood.
Kenobi paled. His lungs no longer seemed to be working. His feet were beginning to lift off the floor, and his curiously constricted heartbeat thudded in his ears. Just before the idea of a fracture first occurred to his ribs, a flash of green blew past him to become a tornado around Ani-- Vader. The unearthly grip instantly abated and Obi-Wan was dropped to his knees. Blood rushed back to his brain, and his thinking accelerated to the inhuman speeds a fight between Force users necessitates.
The portal to the command room, built to withstand the sustained assault of hundreds of Clone Troopers' fire, was buckling under the heat released by the two lightsabers' clash. Vader had planted himself just beyond the doorway, and had not yet allowed Yoda to slip past him into the more open floorspace behind. From this position he could rain down blows onto the ancient Jedi, leaving very little room to dodge. The tiny body quivered each time Yoda was forced to block a strike directly. This arrangement lasted nearly six seconds, an eternity of bladework. In this interval of impasse, two dozen killing blows were exchanged, not one of which connected. The green bar looked more like a fan than a blade, and Vader's own blue fire struck again and again like a jackhammer. Yoda would strike three, four, even five times before actually committing to an attack, drawing Anakin's blade away from attack with any trickery imaginable. The Force allowed mid-air acrobatics unrivaled by any performer, and countered itself with bone-shattering blows batting the green whirlwind out of the air.
Vader finally connected, initiating a saber lock while Yoda was still in mid-air. With the Force already levitating him, the old Master was forced to meet Vader's physical strength with his own. The frail form ricocheted toward the wall and fell in a slump. From his vantage point halfway across the hall, Kenobi could see the Sith prepare to cleave his enemy in two. The Force knotted as Vader bent it to his will and flew to land the killing blow. His third bar of plasma intercepted it just before green flesh met blue fire. Now the dual-chromatic dance of first contact was replaced with a cacophony of aquamarine conflict. Each strike met the impenetrable defense of a Jedi, each counter served only to forestall another attack. The two companions, warriors of a doomed empire, halves of a fighting whole could no more destroy one another than a shadow can escape its caster. Kenobi angled himself to protect Yoda, forcing Anakin to try to reach past him for the kill. Each sizzling slice found itself redirected into open air or snagged and caught on the bulkhead behind. Finally the creature took half a step back, no longer vader on the offensive but Anakin, lost and confused. "You fight just like him, but how can you?" Behind the human Jedi, the green one was rising to its feet.
"I can't believe how closely we're matched. But no impostor will be able to block this!" Anakin, not Vader, thrust his lightsaber dangerously close to Kenobi's skull, only to have it deflected yet again. Along with the plasma came his mechanical hand, letting the hilt tumble out of its grip and replacing it with Kenobi's neck. Mechanical motors are a lot easier to usurp than those biological, and a trademark quirk in the Force saw the bionic grip slip. Flinching as the feedback traveled through his arm and into his nervous system, Anakin-no-longer-Vader saw something utterly unexpected: A blue bar locked with a green one. Suddenly his old Master had returned, replacing the impostor that, despite an exact physical resemblance, had not been his mentor. The impostor posing as Yoda immediately spun into a flurry of strikes, high and low, powerful and feints, to dispatch its former servant. Now, though, the two pillars of fire fell into their practiced forms and redrew battle lines. Where before the only Jedi not replaced by a fiendish conspiracy had to fight against two impostors, Anakin Skywalker was joined by a liberated ally and friend against the green menace.