The Balmorran designers of the six-limbed X-1, who nicknamed the droid "Automadon," gave the machine speed, ferociousness, and a lethal arsenal of weaponry that could match even the Empire's AT-AT walkers.
The X-1 Viper was the size and shape of a Kubindi sun beetle. The Viper was one of the products developed, manufactured and sold by Balmorran Arms without any foreign influence, including the Imperials.
The Viper's six-limbed construction allowed it to stand bipedally on its rear legs while firing a barrage of blaster and laser fire. Its middle set of appendages were fitted with boosted blaster cannons, each equipped with the knockout punch of the turbolaser of a capital ship. Two torso-mounted laser cannons were also concealed beneath the X-1 Viper's chin. Its heavy front pincers were fast enough to capture a low-flying airspeeder and strong enough to maintain its grip while crushing the craft into the ground.
However, the Vipers were effective primarily because of the advanced full-body molecular shielding which they wore as shells. This experimental technology not only blocked most conventional weapons, but also absorbed the energy of a laser blast and used it to charge the power cells of its own weapons systems. It could also absorb other energy weapon fire, such as ion cannons, turbolasers, and energy torpedoes. This battle droid also had the power to shoot these attacks back at their targets. The Viper was designed for supervised combat and had manual overrides in its head.
Designed and manufactured by Balmorran Arms, the X-1 Viper was first intended to be sold to the New Republic. In 10 ABY, the industrial world of Balmorra was brought back into Imperial service during Operation Shadow Hand, the reborn Emperor Palpatine's military campaign against the New Republic. The company's intentions to supply the New Republic with new combat droids were halted by Imperial occupation, but Governor Beltane secretly put the finishing touches on the Viper while his main assembly lines churned out countless SD-10s for the public eye. When the Balmorrans learned that the Emperor was killed at the Battle of Pinnacle Base, the planet's inhabitants took advantage of their newly-found freedom and revolted. Balmorra's massive foundries once again started to manufacture weaponry for the New Republic, thus angering the Imperials.
Following the Emperor's second death, Operation Shadow Hand was taken over by Executor Sedriss QL. Sedriss attempted to reconquer Balmorra and retake its factories for the Empire. A fleet of Imperial Star Destroyers commanded by Sedriss arrived in orbit over Balmorra, forcing Governor Beltane to contact the Imperials. After Beltane refused to surrender to Imperial forces, Sedriss deployed stormtroopers, SD-9s, AT-STs, and the Empire's high-tech Shadow Droids to capture the planetary capital of Bin Prime and its manufacturing facilities in the Battle of Balmorra. However, the Balmorran Defense Force was able to defend the city with soldiers and SD-10s, even while the Shadow Droids caused heavy casualties. Ultimately, Beltane deployed his new state-of-the-art X-1 Vipers. The Vipers bested the Shadow Droids and the Balmorrans won the ground battle.
With his invasion force defeated, Sedriss was forced to contact Beltane and accept his terms of peace. Beltane wanted Balmorra's freedom and in turn the planet would sell its Vipers to the Empire. Sedriss accepted Beltane's demands, even though he vowed to annihilate Balmorra after obtaining the Vipers and their designers. However, Beltane secretly arranged for the New Republic to hijack several Vipers onboard the Imperial Star Hauler Reliance en route to Byss. A task force of New Republic commandos under Lando Calrissian and Wedge Antilles was able to capture the droids and stow away on their cramped innards during the journey to the Imperial throneworld of Byss in the Deep Core. The New Republic hoped to utilize the Vipers to attack the Emperor's Citadel and disrupt Imperial war effort.
Since the Vipers were equipped with manual overrides, the New Republic agents activated the droids upon arriving on Byss. During the Battle of the Emperor's Citadel, the droids took down all opposing Imperial forces, causing havoc and chaos on the streets. The Vipers marched right up to the threshold of the Citadel itself, destroying numerous bipedal walkers, XR-85 tank droids, DP20 frigates, and turbolaser turrets. However, Emperor Palpatine—who had returned in a fresh clone body shortly after the Battle of Balmorra—ordered his new Executor Xecr Nist to deploy alchemically altered chrysalide beasts to engage the Vipers, as their armor only defended against energy blasts rather than physical attacks. The Vipers were torn to shreds by the chrysalide's teeth, turning the battle in the Empire's favor. With the Vipers destroyed, the New Republic was forced to retreat. The surviving Rebels managed to escape thanks to the arrival of the smuggler Salla Zend and her friends.
Eventually Byss was destroyed and Palpatine died for the final time at the Battle of Onderon. Not long after the Emperor's final defeat, an Imperial warlord learned that a criminal syndicate had obtained an X-1 Viper, and so decided to make an example of the threat they posed to his territory by attacking the syndicate's base. During the attack, the warlord's forces entered the base and fought against the X-1 Viper.
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