They stared through the glow, each with a better understanding of the duel ahead. His son's scarred face was composed and focused, anger held in check to better serve his intentions, sharp eyes so clearly taking Vader in as a whole, looking for tells in body-language; the tilt of his head, the line of his shoulders, his weight on his feet.
Was this the boy he'd faced on Bespin? If Vader had held any lingering belief that it could be, that he could maintain control of the situation if his son was lost and it finally came to this duel, then the finely honed assault which gave him barely enough time to think between blows shattered that hope and scattered it to the winds.
How had it come to this? Vader disengaged, pulled back, his own intent lost in the turmoil which was eating at his soul.
But wasn't this what he had wanted?
Darkness exacted a price, he knew that. Better than most, he knew that. But he'd still wanted that power for his son. Still cornered him and bound him and forced it upon him, believing--knowing--it would make him unassailable, intending to turn him on the Emperor.
But hadn't he known that this could happen? That all of that power and capacity could be turned just as effectively on himself, once the boy was brought to Darkness; that Palpatine would know that too, and would seek to take control, would manipulate and plot as he always did?
Yes, but he had gambled--gambled that his natural bond with his son would ensure him good will, when in fact it seemed to do the very opposite.
Because of what he had done, Vader realized! Luke had looked to him for that same acknowledgment onboard the Executor when he had asked Vader to free his companions--some confirmation of a deeper connection--and Vader had turned away without compunction, seeing only his own goals.
What right did he have to ask for those same considerations now? This was his own doing, and he was paying the price...
Or was it the Emperor's doing? Wouldn't it be just like him to stir up all that antagonism and direct it against the one person who had the potential to step between Palpatine and his goal... Gain a Sith and remove a complication in the same act.
Luke came forward again, breaking Vader's train of thought and forcing him to focus on simply withstanding the assault. The boy was finding his own focus now, Vader knew, finding his pace. Which was fast. Very fast.
Both physically, with the speed which he moved in attack and defense, and mentally, always looking for an opening, working several blows in advance of where he was now, leading Vader to check, trying to force him to a mistake.
Vader reached out with the Force, widening his awareness; he was steps away from the wall now, and Luke was too fast for Vader to risk allowing himself to be backed against it with no room to maneuver.
The Audience Chamber itself was nowhere near large enough for a saber duel, though Vader knew this was to his advantage. His son was fast, but Vader had brute strength, and in an enclosed space that was difficult to counter. And it was time to bring it into play.
He stood his ground and for the first time mounted a premeditated attack, twice attempting to lock Luke's blade to his own without success. On the second attempt, as he twisted his own blade about Luke's, both was forced down and Vader took the opportunity to step forward, shouldering the boy back and releasing his two-handed grip on his saber to lash out with his fist.
Luke arched back to escape the sideways blow, realized that he was past his center of balance and launched back into a low, tight back flip, one hand coming briefly to the ground as his blade whipped out behind him to cover the move. Vader took a half-step forward but the boy was already somersaulting effortlessly back again into a high arc which took him well clear to land in a low crouch as his saber swept out horizontally, its tip briefly biting into the stone floor.
He stood slowly, body sideways on, blade held one-handed behind him--inviting an attack.
But Vader was far too experienced to step into such a feint of supposed vulnerability. Instead he moved clear of the wall and waited, breathing labored, surprised at the boy's unexpected skill and deftness both in technique and reaction time, each honed to split-second accuracy.
There was no need to ask where that had come from--Palpatine would not have allowed the boy to fight until he knew he was capable, probably choosing this moment with great deliberation. Had the situation not been so uncontrolled, Vader would have allowed himself some measure of pride at his son's burgeoning expertise, even whilst having those razor-sharp skills aimed at himself. But right now that ability required his full attention to hold at bay, committing his son's unexpected talents to memory for future reference.
Both remained still, each waiting for the other to bring the fight to them. Behind his son, Vader could make out the form of the Emperor, seated again on his precious throne, eyes glowing in the low light, enthralled.
Keeping his saber in one hand, Luke stretched his free arm out beside him to shake it, that shoulder clearly already injured long before the duel had begun.
"My weak side," he allowed, smiling, a strangely genuine act.
"I know," Vader said, glancing meaningfully to Palpatine.
"Then use it," Luke invited.
When Vader said nothing, Luke took several fast steps to the side without stepping closer, forcing Vader to turn to keep him in sight.
"Yours is your limited vision," his son said coolly. "Especially at close quarters. The advantage you gain in strength you lose in restricted sight, when you try to bring it to bear."
"Your leg is injured," Vader parried. "An old injury not yet healed. You landed from your high jump into a crouch to soften the impact. You haven't since taken your full weight on your right leg."
"It will hold."
"For how long?"
"Long enough."
Vader began a slow half-circle, forcing the boy to bring his lightsaber before him as he kept their distance constant.
"You're weak and you're injured," Vader said in bass tones. "You've been forced into a fight your body's still too damaged for. You've made your point--step down."
"You're old and you're slow, father. And I haven't made my point."
That brought Vader's ire up. "Step down or I will bring you down."
His son only smiled. "Then stop talking and do s--"
.
.
Luke broke off as Vader plowed in, saber slashing into an infinity loop to force him back. After two quick backsteps, not wanting to give further ground he countered with the same move traveling in the same direction so that briefly the two scarlet sabers chased each other, creating a blinding barrier of light which neither could cross without allowing the other inside their guard.
But the movement was dangerous, uncontrollable by either party save in ending it, so that it was Luke who finally stopped the it, his other hand darting out to halt his saber forcefully so that Vader's blade finally intercepted, the driving impetus of its speed impacting Luke's blade in a shock of power which reverberated through the hilt and into his shoulders. It was a gamble, to give Vader a free move within his defenses, but Luke took the risk rather than maintain such close quarters, where his father's strength was a huge advantage. Because of this he expected Vader to move in, to try again to turn this into a more physical fight--and he didn't disappoint.
Having brief control of both blades Vader knocked the sabers down as he plowed forwards, shouldering into Luke, brute strength forcing him back. Luke didn't even try to hold his own against it, giving the ground without struggle, refusing to be forced to fight to Vader's strengths.