Obi-Wan snuck through the guards using the Force to guide him for stealth, as he always had whenever he had to resort to such an approach, taking the guards down with silent but swift blows to prevent them from being a nuisance later, as he made his way to the security room.
As soon as he arrived, up to 20 Purge Troopers immediately attacked him, but Obi-Wan remained calm. Memories of decades of war flowed through him seamlessly as the old legendary Jedi Master steadily regained his form after his previous battle with Vader and spars with Cal, as he skillfully deflected the blaster bolts fired by dozens of them, before engaging and killing off scores upon scores of the Purge Troopers in close-range combat, skillfully deflecting attacks before returning with several aggressive techniques, mixing Form III with Form IV with a similar level of efficiency to his old self.
Soon, they were all slain, and Obi-Wan gave a small breath as he allowed himself to feel his return to shape before he proceeded to disable the security, calling upon his experiences with slicing as he overrode as much of the security as he could, especially those around Leia's held place.
With all that he could do done, Obi-Wan called Cal. "Cal? Cal! I've disabled the security, but the whole Fortress has been alerted. We got to save her and then get out quickly!"
But Cal did not respond, and Obi-Wan's calls fell into deaf ears.
Until he felt it.
A sudden massive burst of Force power, dark and light mixed together, reminding Obi-Wan of the presence of Dooku, although this presence was less dark than the Sith Lord, the power of the Light Side of the Force still there, but twisted by the Dark Side.
His eyes widened in horror as he realized who it was. He could feel the emotions of pain, anger, horror, and grief fueling the outburst.
Vader was not here, so there was only one other person capable of such power.
Cal!
It had taken a few minutes before he managed to find the Jedi who had helped him, all while unable to stop himself from being seriously unnerved at the sight of the various corpses from Cal's slaughtering.
All of it contained strong traces of rage and the power of darkness, with tinges of the light focusing that anger but unable to quell it.
But what he had just seen was truly fearsome indeed.
Cal had been restrained by a few Purge Troopers, only for him to release a burst of the powers of death over the Force, slaughtering them all, as he broke out of the restraints with sheer raw strength.
"Cal!" Obi-Wan shouted, but instead of stopping, Cal turned backwards and Obi-Wan only narrowly managed to get his lightsaber to block Cal's attack.
Cal's expression was that of a man who seemed lost in a hazy yet cold dose of fury as he attacked Obi-Wan with a vicious yet lethally effective bladework that reminded Obi-Wan of the techniques once used by Anakin and Maul.
Obi-Wan deftly blocked several aggressive spinning strikes as well as brute-force wide strikes from Cal's double-bladed saber, but found it difficult to break through the surprisingly accurate defenses in Cal's technique with this form of dueling, even more so as Cal made more use of Djem So's brutal counters after parrying. Nevertheless, Obi-Wan was patient and determined. He had to get through Cal before he became too lost in his rage.
Just as Obi-Wan had pushed Cal back, though, Cal shifted into Jar'Kai, making things more difficult for him. From what he had seen, dual-wielding was Cal's most effective combat technique, as he could blend in techniques from several forms more seamlessly due to having two blades to duel with.
Not only that, Cal had clearly learned and improved his skills from experience, and he had fought Vader more than Obi-Wan did, as made clear by how he replicated some of Vader's techniques into his style.
Obi-Wan... Focus. Guide him through the darkness. Save him.
Master Qui-Gon's voice reached Obi-Wan, and he hardened himself after being thrown into a nearby wall using the Force, allowing the Light Side of the Force to guide him, to strengthen him.
He fought with all his strength even as Cal continued to keep up with him, his current mindset throwing in all the skills he had in the most brutally effective way, slowly but surely gaining an edge.
He did not only defend himself, but also fought back with techniques from Ataru, Shii-Cho, and Djem So, remaining cautious but firm as he pushed back the Jedi before him who could still be saved.
It had eventually ended with Obi-Wan disarming Cal.
"Come to your senses!" Obi-Wan shouted as he pushed Cal back hard.
However, this caused Cal to snarl as he proceeded to grip and lift Kenobi with the Force.
Obi-Wan struggled to break free, but he eventually decided to capitalize on this moment.
"Cal! It's me, Obi-Wan!"
Cal froze as the yellow colors of the Dark Side began to leave his eyes.
"You reminded me of how I still had so much to live for, despite my failure. Don't follow this path! Come back!"
Eventually, Cal released him and Obi-Wan watched as he stumbled back, clutching his head as though in pain.
"W-What have I done?"
Obi-Wan went forward and gave him a brief but firm hug. "Tell me what happened."
As soon as Cal let out that roar, he ended up freeing his other enemies, causing them to fire at him, but Cal did not even blink as he raised his hand and used the greater strength he had in the Force to deflect the blaster bolts straight at the Purge Troopers who fired them.
When the Fourth Sister moved to strike him with her lightsaber, Cal stopped the blade using the Force alone without even blinking, even as the Fourth Sister struggled using her own powers with the Force, as he stared at the corpses of his fellow Jedi.
Without any further ado, Cal crushed the amber blocks preventing the bodies of the Jedi entombed here from passing on to the Force with a brutal clench of his right fist, while his left proceeded to exert such vicious yet precise telekinesis as to break down the Inquisitor's lightsaber in all it's parts before crushing it, causing the kyber crystal itself to explode, sending the Fourth Sister flying far away while Cal was only knocked back a little.
Cal did not even care to check on the Fourth Sister as he stared at the corpses of his fellow Jedi, their bodies beginning to fade into the Force as they should be.
How much more perversion of the Jedi Order would the Empire make? Was this really how far the Jedi had fallen? Are there truly so little regard of the Jedi in this galaxy? AFTER ALL WE'VE FOUGHT FOR IT!?
Fury continued to fuel Cal's power in the Force as he marched forward, rage over the unjust fate of the Jedi and the ways of those who had fallen getting over to him.
Cal was almost certain his expression was terrifying as all kinds of enemies were cut down without batting an eye, recalling the few books he had read about Vaapad and Juyo as though on instinct and mixing their brutal techniques with vicious applications of the other lightsaber combat forms, in particular recalling the aggressive techniques of Anakin Skywalker that he used against Obi-Wan before and even some of Vader's moves when they fought. It was as though his mind was sharpened aggressively, his combat technique brutal but efficient as he hacked off limbs and cut off heads without a care.
The Force was called upon much more easily as well, and in straight up lethal forms as Cal froze up to a kilometer radius of enemies while cutting them down with bursts of force-enhanced speed, and it only grew easier to wield the powers of rage as he went further into it, snapping the necks of imperial officers despite their pleas for their lives and redirecting blaster bolts back to their firers or to their allies. What was most terrifying was that Cal even had the capability of conjuring Force Lightning, blasting down various droids whose model meant nothing against Cal's wrath with streams of red lightning and sparing no thought at electrocuting a few Purge Troopers to death as well.
He couldn't bring himself to stop, the images of the crew he lost on Coruscant and the recent revelation of the desecration of his fellow Jedi fueling his righteous hatred towards
His rage was only temporarily stopped when dozens upon dozens of Purge Troopers marched at him, attempting to defeat him with tactics combined with superior numbers, and even as Cal continued to mow down their combined efforts, stun cuffs were thrown at him and managed to land on his hand eventually, disarming him of his lightsaber. However, this proved to be a fatal mistake, as Cal's rage was beyond any restraints power to contain.
He unleashed all the world-weariness, rage, and grief he accumulated over the course of years since Order 66 in a wave of maleficent power, killing every single purge trooper and releasing him from the stun cuffs.
"Cal!" Cal turned around and attacked whoever it was behind him.
He didn't recall much of the moments, only that the fight went back and forth, one gaining an edge over the other before the odds were turned back against them.
What eventually ended the fight was Cal being disarmed of his lightsaber and someone shouting at him to stop, causing Cal to snap and grip his enemy with the Force.
"Cal! It's me, Obi-Wan! You reminded me of how I still had so much to live for, despite my failure. Don't follow this path! Come back!" Cal stopped at those words as his senses and faculty returned to him, realizing the person he was trying to kill was none other but his fellow Jedi and ally.
Obi-Wan breathed deeply as he was released from Cal's power, while Cal stumbled back, horrified at the sight of various corpses around him, remembering the various ways with which he slaughtered the guards here.
"What happened?" Obi-Wan asked delicately.
And so Cal told Obi-Wan about it all, admittedly a bit fixed, as he still struggled at the realization of what he had just done, the power that he had commanded still within his grasp despite returning to the light.
By the end of it, Obi-Wan gave him a look of understanding and sympathy. "I understand, Cal, but you have to stay in control. Don't overuse such powers, or else you'll be no better than the Sith. No one is perfect, but if you can go back and be better, that's enough."
Obi-Wan firmly shook Cal's shoulder at those words. "That's how you reached me. You showed me how the galaxy is still worth fighting for. Now, I'll do the same to you. Don't forget that."
Cal gave a small grateful smile as he nodded. "Thank you, Obi-Wan."
And so they reached the room where Leia was held, the very same room where he once fought Trilla for the holocron, Cal taking out the Stormtroopers silently while Obi-Wan freed Leia.
Leia immediately hugged Cal as soon as he finished. "Cal! Obi-Wan! Thank goodness you're alright. They told me you had to retreat from Vader. I didn't tell them anything, but-"
"Come on. Let's get you home." Obi-Wan said in a hurry as Cal nodded.
They wanted to escape through the same halls where Cal had taken out every single troop stationed there, but when they were there, the Fifth Brother was fuming over the loss of so many soldiers, so they had to find another way.
And unfortunately for them, it just happened that the path they chose was full of imperial troops.
"Stay back! I'll deal with these." Obi-Wan said firmly as Cal nodded, understanding the meaning that he shouldn't engage in fights right now due to his compromised emotions.
Fortunately, Obi-Wan alone proved to be enough, and Cal watched with apt attention as Obi-Wan demonstrated abilities that had once earned him one of the top spots in their Order, cutting down scores upon scores of enemies without Cal needing to help aside from deflecting a few stray bolts.
He seamlessly changed his dueling style between defense and offense as he took down numerous soldiers by either blast-deflection or close-combat, and he no longer shied away from blending in techniques from various lightsaber combat forms, expertly jumping and spinning as he avoided attacks and took down a couple of droids with Ataru, deflecting blaster bolts as natural as breathing like the true master of Soresu he was known for being, comfortably shifting between one and two hands like a master of Makashi would, and applying the fluid to aggressive techniques of Form V with a style that befitted the teacher of Anakin Skywalker.
Not only that, Obi-Wan did not hesitate to use the Force in various masterful ways like a proficient user of Niman, such as ripping away blasters when an enemy is too numerous, crushing droids, pulling a trooper to shield against a rain of blaster fire, and even absorbing blaster bolts before releasing the energy back.
Cal allowed a small smile to come across his face as Obi-Wan simply flexed his muscles, as though only minorly affected by his single-handed massacre of the soldiers of the Fortress.
"Come on. Let's go. You've called them, right?" Obi-Wan asked as Cal nodded.
"Yeah. A minute ago. They'll be here soon, and fortunately, this path is straight-forward. Come on!"
"My lord! Reports have come from the Fortress. They said that Cal Kestis slaughtered up to 35% of the Fortress's guards using destructive powers that reeks of the powers of the Dark Side!"
Vader's eyes widened behind the mask of his armor. Kestis was able to not only increase his combat prowess, but also harness the Dark Side openly?
"Hurry, my Lord! Kestis and Kenobi are decimating the Fortress Inquisitorius! Casualties are increasing by the minute."
Vader frowned. It would still take approximately 5 minutes before he could reach Nur, having just taken off from his castle on Mustafar.
Nevertheless, Vader didn't particularly care about the damages. While losing the Inquisitors personally trained soldiers would be a few hinderance, if Kestis was powerful enough to cause that much damage, then if Vader could secure him, it would make up for all the damages done to Fortress Inquisitorius.
Not only that, the girl who might well be his daughter and his son would be his if Kestis were to be captured. Kenobi would die, too, and Vader was sure Sidious wouldn't care about the losses besides admonishing Vader for the operation costing so many men, which would promptly be dismissed once Vader showed Sidious Kestis's potential, more than enough to replace the loss of a few dozens of Inquisitors.
"There they are!" Cal noticed the Fifth Brother and the Third Sister shouting as they charged at him and Obi-Wan.
They were at the entrance, having sneaked out after taking a few clothes from the Imperials he killed, after overhearing reports of Vader approaching dangerously close to arriving on them.
"I can use a Blaster and help as long as you guys can cover me!" Leia shouted as Cal and Obi-Wan fought side-by-side, deflecting the tons of blaster bolts fired at their direction.
"No need. I can sense our tickets out of here approaching." Cal said with gritted teeth as he kept cutting down soldiers after soldiers, either by deflecting the bolts back at them or slaying them himself.
"There!" Obi-Wan shouted, and Cal watched as a speeder and the Mantis came rushing forward, the speeder covering the Mantis as it fired at the troops, distracting them enough for Cal and Obi-Wan to reach near the Mantis successfully.
But then, a shot managed to almost kill Leia, Cal barely reacting in time to push her to Obi-Wan, which still left her with a scratch as the bullet scraped her shoulder.
At the sight of Leia's pain, Cal allowed just one last burst of darkness, focusing more on his desire to save Leia and the memories of his friends rather than the anger.
He suspended all the blaster bolts nearing them, deflecting them to spots that were of no danger to his allies, before focusing the lightning into a small ball of energy that he threw at the ground.
As soon as it hit a few Stormtroopers, it exploded and Cal didn't look back as he, Obi-Wan, and Leia fled on the Mantis.
"Are you okay?" Leia said softly as Cal meditated, trying to balance his feelings and regain all of his composure.
"I'm fine, Leia. How's your injury?"
"It's fine. Just a scratch." Leia said with a shrug.
"It was quite fortunate you had such reflexes, my friend." Obi-Wan said in relief, although he soon turned serious when Leia left.
"How are you feeling?"
"I feel as though I still have more power than I did before. It's not nearly as overwhelming, but I can still feel it's there." Cal said as Obi-Wan frowned.
"Stay strong, Cal. I won't let you lose yourself like Anakin did."
Cal gave Obi-Wan a small grateful smile as he nodded.
"YOU! WERE! WARNED!" Vader snarled out as he proceeded to force-choke the pretender of an Inquisitor before him in his rage. "WHAT DEFEAT... WOULD BRING!"
This was quite the defeat indeed. Not only had they failed to keep Kestis and Kenobi contained enough for Vader to arrive, but they also failed to even keep the girl in custody.
Vader was certain now that she was his daughter, as soon as he arrived on the fortress, only 2 minutes after Kestis's successful escape. He had stumbled upon the blood of the girl caused by a stray blaster bolt, and as soon as he touched the spot of the ground where the Force told him to, he was struck by a vision.
Padme was dying, but she was surrounded by twins. A boy and a girl. She had named the boy Luke and the girl Leia, just like what he had seen in Kestis's mind.
Leia Organa was without a doubt his and Padme's daughter. That would have left him with only Luke to find, had it not been for this failure.
"A... Tracker!" Vader's eyes narrowed as he threw the Third Sister aside.
"I put a tracker on the ship. Soon, Kenobi, Kestis, and the location of whatever organization is backing them will be ours."
Vader said nothing to that. He could read her mind easily enough to know it was true, but it did not stop him from feeling anger at the delay.
"My lord, the base has suffered severe damage. Most of our specialized forces are dead! All those years of building our army up to counter Jedi, now most of them have been vanquished! Because of her!" The Fifth Brother shouted but Vader simply turned his attention towards him.
"Well, Kestis has surely demonstrated capabilities that would be worth the loss, if he was able to demolish this Fortress." Vader said coldly as the Fifth Brother frowned but dare not say anything.
"Lord Vader, the Fourth Sister is dead, and there has been some serious damage to the Fortress. You should check it out first. We have managed to get recordings of the battle, too, my lord, if you wish to see them." A Stormtrooper came in as Vader nodded.
He traversed through the series of corpses littered around without saying a word. He could still feel traces of the power Kestis commanded with the Dark Side, the power that could have been used for his cause of overthrowing the Emperor soon had it not been for the failure of those incompetent fools.
When Vader reached the room the Stormtrooper pointed him at, he sat at the chair given to him as Kestis demolished the Fortress's defenses.
It started out when Kestis saw the Jedi Tomb beneath the Fortress, the sight being such a last straw that he channeled the Dark Side without hesitation. That scream was almost surely the burst of power he could feel from Mustafar, but that was only the beginning.
Vader had to admit he was impressed by Kestis's abilities already when they fought again on Mapuzo, but this all but confirmed Vader's suspicion. Kestis truly had the markings needed to be his key in overthrowing the Emperor.
The way with which he fought with a lightsaber under the thrall of the Dark Side was astonishingly instinctual, yet equally impressively competent and deadly, and Vader could tell he had learned a few of those techniques from their duel before. His abilities with the Force was also quite exemplary, performing grand feats of telekinesis that even Vader had to admit was worthy of praise, especially so as he called upon the same powers of lightning as Sidious himself did.
Even more impressive than the butchering of those men who proved to be powerless before the wrath of his potential apprentice in the future, however, was his capability to combat Kenobi as effectively as he did.
Granted, Kenobi had held back, but he had clearly regained most of his edge after their duel on Mapuzo, yet he still was pushed to his limits to overcome Kestis despite having regained strength close to his prime.
And Kenobi did not even truly win the battle. He had disarmed Kestis, but Kestis had tapped into his rage and restrained Kenobi. Had it not been for Kenobi giving up on fighting and focusing on reaching out, there was a chance Kestis would have fallen to the Dark Side, which further increased Vader's ire towards Kenobi.
All this while his training was still yet to be completed truly...
So be it. If this was the Force's way of giving him hope to overthrow the unworthy Emperor, then Vader swore he would not squander this.
He would have Kestis, and he would have his children.
Darth Vader swore on it.