Long before Luke Skywalker finally managed to bring Darth Vader back to the light side, the former Jedi was almost redeemed by his short-lived green lightsaber . While Jedi construct their 'sabers as part of their training, the Sith have a different tradition - gaining their red lightsabers by taking a Jedi's weapon, then 'bleeding' the Kyber crystal inside to infuse it with their pain and rage.
But while this is how Vader eventually got his iconic red lightsaber, the process was almost enough to turn him away from the Dark Side. In Star Wars: Darth Vader #5, Vader sets about bleeding the Kyber crystal of Jedi Master Kirak Infil'a, who he brutally murdered after initially being bested by the skilled warrior. With the green lightsaber in his possession, Vader deconstructs the weapon. After an initial attempt to corrupt the crystal, Vader is thrown back and knocked unconscious, experiencing a Force vision where he reassembles the lightsaber, then kills Palpatine with its green energy blad
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