During the blockade of Naboo, one Jedi, named Bil-Li Reinharth, grew concerned. He sensed a growing presence of the dark side of the force, along with some unknown man's plot to destroy the Jedi. If the Jedi were destroyed, the galaxy would be openly vulnerable to the dark side, the Sith, and the evil that would conquer the galaxy.
Thinking hard, Bil-Li got an idea: He could create 'Jedi-Droids' to take up the mantle. In a secret workshop he built into the walls of the Jedi Temple, he would take used protocol droids, adjust their bodies so they could move their arms and legs like people.
He would then program their knowledge with the lightsaber and force attack techniques of the order's greatest knights. He spent his spare time collecting lightsaber crystals from planets like Ilum, and spare parts from planets like Raxus Prime, to build lightsaber for each droid. He rigged the droids' hands with magnets to mimic force-levitation and miniature fans to simulate force-pushing. He also hooked springs into their legs to give them super Jedi jumping abilities. And for one precaution, he gave them partial artificial intelligence (A.I.), so they could watch and learn enough to assess the enemy to counter attack or find the strategic flaws.
Bil-Li hid away his workshop and droids, afraid the council wouldn't approve his idea. At the end of the Clone Wars, when Darth Vader (Anakin Skywalker) led an army of clones in an attack on the temple, Bil-Li hid with his droids inside his workshop, he was the only one who knew about it. After fighting through the clones and seeing Obi-Wan Kenobi and Yoda (2 survivors) do the same, he decided to smuggle his droids off-world and would take them with him into hiding, until 30 years later, when rebels rose up against Palpatine's Galactic Empire. Then, during the Galactic Civil War and the Resistance's battle with the First Order 30 years later, Bil-Li, his newly gained family (soldier wife and force-sensitive son), and his army of Jedi-Droids battled across the galaxy to vanquish the dark side.
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