The raid on Darvannis occurred when the Mandalorians attacked the planet Darvannis as part of the Alliance's war against Zakuul in 3630 BBY. After SCORPIO revealed that the GEMINI droids were produced from a single template called GEMINI Prime in the Darvannis factory, the Alliance leadership decided to retrieve it, although they did not have enough forces for a major assault. Theron Shan responded by calling in a favor to Shae Vizla, now holding the title of Mandalore the Avenger, though a group of Mandalorians would desert the Clans, under the leadership of Mirli Lok into forming the Ash'ad. The Alliance Commander traveled to Darvannis, where Vizla's Mandalorian clans were itching for both payback against the Eternal Empire and a chance to re-arm themselves with the spoils from the factory. Mandalore's best scout Torian Cadera joined the Commander in capturing the perimeter guns and reprogramming them to target the weapons factory, while Breyer Chorn and his forces took down the factory's shield generator. Afterwards, Vizla informed the Commander that the fighting would resume the next day after her troops had some rest. The next morning, Torian again joined the Commander in neutralizing the enemy forces at the Zakuulan listening post, while Shae Vizla and her second-in-command Khomo Fett led the attack against the factory's power stations in preparation for the main assault. With the factory's power stations taken over by Clan Beroya and Clan Fett warriors, Shae Vizla gathered her warriors to rally them before leading them inside the factory to claim as many weapons as possible, while Torian accompanied the Commander on a mission to secure the GEMINI Prime. The Commander successfully removed the droid from her alcove, while the Mandalorians retreated from the factory. In the aftermath of the battle, Torian asked the Mandalore to join the Alliance as her representative, and after Vizla granted his request, traveled to the Alliance base on Odessen along with the Alliance Commander.
During the Eternal Empire conquest of the galaxy Mandalore the Vindicated fell in combat and many of the Core Worlds were blockaded by the Star Fortresses, trapping almost half of Mandalorian clans on those worlds. Most of the other clans had scattered, and Shae Vizla became the new Mandalore. In 3630 BBY Vizla was contacted by Theron Shan, a representative of the Alliance that opposed Zakuul, who offered the clans a chance to strike back against the Eternal Empire by assaulting the weapons factory on Darvannis. The factory produced starships, weapons, skytrooper droid forces and boasted fully automated defenses, including kilometer-deep tunnels, energy shielding, defensive turrets and anti-infantry ground cannons. For the Alliance, the goal of the attack was to retrieve the GEMINI Prime, a template for the GEMINI droids which could be the key to taking over Emperor Arcann's Eternal Fleet. Vizla accepted the offer, seeing not only an opportunity for payback, but a way for Mandalorian clans to re-arm themselves for the first time in years.
Mandalore the Avenger led the clans loayl to her onto Darvannis.
Having assembled a dozen of clans, including Fett, Chorn, Beroya, Cadera and Farr, Vizla led them to Darvannis, with Khomo Fett as her right-hand man. Having established a camp well outside the range of the factory's guns, the Mandalorians have laid siege to the factory, placing rotating assault teams of two hundred commandos each around it and sending scouts to determine the factory's defenses. Shae Vizla and Khomo Fett were soon joined by the Alliance Commander, who arrived to assist with the assault and personally retrieve the GEMINI Prime. Vilza paired the newcomer with her best scout Torian Cadera and send them to capture the perimeter defense guns and reprogram them to target the factory itself. Meanwhile, forward teams led by Valk Beroya and Breyer Chorn moved to take down the factory's energy shield generators. The factory's perimeter was patrolled by both skytrooper forces and Eternal Empire Walkers, which Torian and the Commander faced while reaching the guns in sector nine, while Valk Beroya fought her way through sector four, losing several warriors along the way.
Khomo Fett was Mandalore's second-in-command during the battle.
After losing Hashar and a dozen other more warriors, Clan Chorn forces reached the shield generators and rigged them with explosives. However, the remaining warriors were outflanked by skytroopers and unable to withdraw, holding their ground as the detonations took down the factory's shields. Breyer Chorn then contacted Torian Cadera, giving him a green light to fire the factory's guns at their position, preferring to die in an artillery strike rather than to fall to a bunch of machines. Torian agreed, but the Alliance Commander intervened and ordered Torian to retarget the guns, giving Chorn and his forces a route to withdraw instead. In the end, that wave of assault cost the lives of twenty-eight warriors, but the factory's shields went down and the inner ring of defenses had suffered severe damage. The day coming to close, Mandalorians held a Kote ky'ram Death Ceremony for their fallen comrades, while celebrating their own survival during the night.
Eternal Emperor Arcann personally observes the battle progress.
The next morning, Vizla send Clans Beroya and Fett to take the factory's north and south power stations respectively, to weaken the skytroopers for the final push. When Torian noted that this put air and sniper units at the Zakuulan tactical post in a position to outmaneuver the clans, the Commander volunteered to keep the droids distracted long enough for the Mandalorians to reach the power station, with Torian again joining their side. Vizla and Fett themselves led this assault, in which Valk Beroya's team lost Yenko Farr and his three sisters. Torian and the Alliance Commander successfully contained the droids, and after both power stations were down, Vizla asked them to shut down factory's perimeter sensors in order to cover their retreat. Torian watched over reinforcements while the Commander shut down the sensors, after which Lana Beniko made an unexpected call, providing the Commander with detailed schematics of the factory obtained by Theron Shan, to better plan the assault.
The Alliance Commander located the GEMINI Prime.
Ready to move inside the factory, Vizla shared her battle plan with the Alliance Commander, who added to it by providing the factory schematics. Vizla gave a rallying cry to her warriors and went to lead the assault herself, leaving it to the Commander and Torian Cadera to retrieve the GEMINI Prime. Inside the factory, Khomo Fett led the warriors to the armory, while Jos Beroya's men ambushed the security office and Dalash Ard demolished the skytrooper assault force with ion bombs. The schematics led Khomo and his warriors straight to the armory, where they picked up two dozen plasma cannons and went to assist the Mandalore, while Valk Beroya went for the factory's main reactor, even though she was down to three warriors by this point. Meanwhile, Torian and the Commander encountered and defeated skytrooper ZT-001D, after which a few hundred skytroopers were deployed to their location to protect the GEMINI Prime. Torian volunteered to hold them off, while the Commander located the Prime and removed the droid from her alcove, shutting her down. The template unit was secure and the Mandalorians were able to secure a sufficient amount of weapons and deal enough damage to the factory before Vizla ordered an organized retreat.
By the end of the the day, the factory was intact, but mostly offline, while the Mandalorians claimed enough plunder to re-arm themselves. In the aftermath of their victory, Khomo Fett and the other warriors felt a renewed vigor for battle, which troubled the Mandalore, who was afraid that the search for glory would lead clans against another opponent sooner than they were ready. The Commander convinced her to find a suitable outlet for their bloodlust, and Vizla agreed to Torian's request to join the Alliance as her representative. The Commander and Torian returned to Odessen, where SCORPIO analyzed the GEMINI Prime and explained that by plugging the Prime into the captain's console on any warship in the Eternal Fleet, she would be able to take control of the entire GEMINI network, and with it the Eternal Fleet itself. Identifying a lone warship scheduled to recharge its hyperdrive as their target, the Alliance leadership moved to intercept it. Shae Vizla herself later traveled to the Alliance base on Odessen, formally adding her strength and that of her warriors to the Alliance's cause. The Mandalorians, led by Torian Cadera, would go on to fight in the liberation of Voss and defend the Alliance base during Vaylin's assault on Odessen.
During Star Wars: The Old Republic: Knights of the Fallen Empire Chapter XIV: Mandalore the Avenger player is faced with three major choices. There first is to whether to allow Torian Cadera to fire an artillery strike on Breyer Chorn and his forces, with the Light Side option to forbid him, Dark Side option to encourage him, or a neutral option to leave the decision to Torian, which gains his approval and leads to him firing the guns anyway, killing Chorn and his men. The second is whether to share factory schematics with Shae Vizla before the assault, with the Light Side option leading to Mandalorian victory and the Dark Side option resulting in their defeat, with many warriors including Dalash Ard dying while navigating the maze of factory tunnels, and the remainders being too few to carry a sufficient amount of weapons. In the aftermath, if the battle was victorious, player can respond to Vizla's concerns with a Light Side option encouraging her to stop the clans from endlessly looking for a new war, a Dark Side option encouraging her to attack the player's opposing faction (either Sith Empire or the Galactic Republic) or a neutral offer to replace Zakuul's skytroopers after the war ends. If the Mandalorians suffered a defeat, player can respond with a Light Side option by sharing the responsibility for it and offering Alliance resources and manpower to strengthen the clans, a Dark Side option to further undermine Mandalore the Avenger in front of her warriors, or a neutral option promising that the losses were necessary to beat Zakuul.