"Its a setup, DarkHawk! Listen to me, Takagari!"
Locke did his best to press DarkHawk back, never relenting as he steadily assaulted the other man. DarkHawk put up an effective defense, even with one lightsaber. He was fast, but Locke could tell that he was slowly being worn down.
That left more room for words. Locke had no intention of seriously harming the other man. Sadow needed him. Whoever had set this up would want them to kill each other. Locke wouldn't have that.
"Of course, you say that," DarkHawk answered through gritted teeth. Locke saw sweat on his forehead. DarkHawk was an ambush predator; a hunter. Locke saw that now. In his time as Consul, he had never bothered to pay attention to the Sith and the others in Marka Ragnos. He had assumed them safely under Muz Ashen's watch.
He really hoped Muz was not behind this.
That was ludicrous, but Locke didn't know what to believe any more. He had led the Brotherhood to that terribly destructive civil war over Korriban.
Focus, he told himself. How can you convince DarkHawk? The other man had an astute mind. He would not be convinced by Locke's mere statements.
As his attempts failed, Locke began to suspect that he would have to do something rash. No. He had always been cautious and scoffed at such tactics. He couldn't give that up.
DarkHawk knew as well as Locke that he was tiring, so the Augur suspected something desperate. He did not, however, expect DarkHawk to be so good at it.
The Battlemaster dropped a flash-bang grenade at his feet, but failed to trigger it. Either he had somehow messed up, or-
Locke glanced up, seeing lightning arc toward him. It hit his body, causing his nervous system to feel as if aflame. Locke roared in frustration and agony. He turned, leaping toward the ground, dodge-rolling away from DarkHawk. Heart beating loudly in his ears, the Augur came up to a crouch and looked around, lightsaber prepared.
DarkHawk was nowhere to be found.
Breathing deeply, Locke slowly stood up, looking around the chamber. In the dim light, there were many places to hide, especially with the unique architecture.
"I'm not the enemy," he said slowly," Sadow is everything to me." His voice was cold. There was no emotion. He did not blame DarkHawk for thinking that he had fallen.
He had fallen, after all - to the dark side - but he had not betrayed his Clan.
"Why should I believe you?" DarkHawk said.
Locke took a step toward one of the statues, trying to pinpoint where the other man hid. The Augur flared his presence in the Force, pushing it against the surrounding environment, mentally searching for the quiet eddies that would indicate the Sith's presence. He had to be nearby, but...there. The gentle waves of Force energy were not disturbed by stone or by flora, but they were by life.
Turning toward where DarkHawk hid, Locke stopped. He saw nothing.
"Because," Locke said softly, forcing the coldness from his voice. He threw his lightsaber aside, his eyes intent on the darkness where DarkHawk hid. "Sadow's my life. The Brotherhood is collapsing. Would I go to the Inquisitorius? I sacrificed half our fleet to protect our people!"
His mind went back to that day: the death; the chaos. It had not been orchestrated. There had been no carefully-calculated decision. It had been a mad scramble for survival.
He had been a fool, but he had to convince DarkHawk.
"Please DarkHawk, if you don't believe me, strike me down." He had to count on the other man's deductive reasoning now. DarkHawk seemed clever; Locke just hoped it was the right amount of clever.
A wraith-like shape slowly emerged from the darkness, DarkHawk's remaining lightsaber igniting with it's distinctive snap-hiss as the Sith came into view. He slowly approached, aiming that lightsaber directly at Locke's chest.
Locke breathed deeply, forcing himself to stand firm.. "I am not the enemy," he reiterated. "But they want us to fight."
DarkHawk tilted the tip of the lightsaber upward, forcing Locke to lift his chin to avoid being scarred. At least if I die, I will die with my dignity, he thought.
The two locked eyes. Finally, DarkHawk shut down his lightsaber. He slowly walked past Locke, but the Augur did not move, breathing slowly.
"I believe you," DarkHawk said quietly. Then, in one fluid motion, he spun around, hitting Locke over the head. The Augur collapsed, blinking spots from his eyes. It was hard enough to see in the darkness, but still he turned his head toward DarkHawk, tasting blood.
"Why then?" he whispered.
"You lied," DarkHawk answered, keeping his back to Locke. "The fleet was a route. Anyone could see that. There was no valiant sacrifice. You cannot save your reputation, Son of Sadow." The last bit was almost a growl. It felt like a knife to the heart. DarkHawk had always exhibited so much respect; so much honor. If he spoke so, then he had truly changed his mind about Locke.
He must despise me, the Augur thought.
DarkHawk collected his errant lightsaber and departed silently, disappearing into the dark.
Locke remained on his knees for a long time, staring at the stone ground. He had won a victory in that he had managed to convince DarkHawk not to kill him. At the same time, he had suffered a great loss in losing the man's trust.
What is happening to me? he thought. His grip on the world was slipping. His leadership had proved inadequate and lost him the respect of the people in Sadow's domain. Now, not even the Sadowans who would once follow him blindly into battle believed in him.
Still, he had to continue on. He had survived. He had to find whoever had set them up, and set that right, at least.
That small goal pushed Locke to stand up and depart Dromund Kaas.
Syntax
This is slightly repetitious with your use of "lightning". Your wealth of descriptors between them assuages this somewhat but it is still something to keep in mind and avoid to ensure the flow remains fresh.
You probably realized at some point after this that his last name is "Sonjie".
You should use markdown formatting to splice out your "thoughts" from the narration. In this case you would bookend "But why?" with an asterisk (*). In its current state, I had to presume based on context what was thought and what was narration.
This should really be split up with some punctuation, otherwise it is a broken sentence. Either a period between "hiding" and "if" or even a semi-colon.
"this" reads odd here. It would flow better as: "the once great sanctuary".
Some more repetition with "knew". This would be better written as: "Locke knew the voice; he recognized it as DarkHawk's."
This gives the impression of present tense. Would read better as: "Locke could not pinpoint his location at that moment."
This would be one of the rare cases where I recommend that these should not have been made to be separate sentences as they read now. Mostly it's the "moving" that causes this. It reads as connected to a larger sentence that just isn't there. It would work as is if you changed the second sentence to this: "Once again, he moved his hand closer to his saber."
Missed a comma here.
The comma here isn't needed. You lead into dialogue with a comma when it is part of the previous sentence. In this case it isn't, but is connected to "he asked" instead. As such, you'd close with a period then begin the dialogue as you have it here.
This should be "slid".
As a general comment, you use the "double-space after a period" method in your writing which is a holdover from the days of typewriters. As such, there's nothing wrong with that, but if you're going to do it you should be consistent. There were a few places in your post where you used only a single space instead of two.
Story
We're big on discussing "show, don't tell". This is one of those times. Don't name the power, such as "Force pushed". Show it to us. As an example: "Locke reached out to the Force and guided it with a thrust of his palm towards the Battlemaster. The energy rush pushed the battlemaster out of the way"
This is just confusing. The "headmaster" is an actual role within the Brotherhood society. Locke would have been your former Consul, not headmaster.
The biggest issue I have with this post from a judging perspective is that you wrote this story with the intention of cooperation. This is not a cooperative competition, but fights between these characters. It would need to be specified as cooperative. Even further beyond that, the only "conflict" in this post is that single sniper shot. We require more than that to constitute a full post. Each segment of an ACC bout should have conflict between the participants (unless cooperative, then with others) as that is the primary story focus. The conflict. The rest is fluff to make that conflict more palatable. Keep that in mind in your writing.