During her internal conflict with the dark side of the Force in Star Wars: The Rise of Skywalker, Rey sees a vision of herself as a dark side user, armed with a lightsaber with a fascination connection to Kylo Ren. Kylo Ren’s lightsaber dazzled Star Wars fans in the first teaser for Star Wars: The Force Awakens, with the Knights of Ren weapon differentiating itself from more familiar Sith lightsabers by having both a crossguard and an unstable red blade. The envisioned double-bladed lightsaber of Rey’s dark side doppelganger has a pair of unstable red blades, and the origin of Kylo Ren’s weapon provides a possible explanation for how such a weapon might exist in Star Wars canon.
Kylo Ren is an astoundingly powerful dark side user in the Star Wars sequel trilogy, though he’s a Knight of Ren, not a Sith Lord. His lightsaber, as revealed in Star Wars: The Rise of Kylo Ren, is the same weapon he used as a Jedi, but its Kyber crystal was removed and “bled” via dark side-induced torture, turning it red but cracking it in the process. The crystal became volatile and dangerous, requiring Kylo Ren to build crossguards into the lightsaber, venting the excess energy to stabilize the blade while also providing additional offensive and defensive capabilities.
Related: Rise Of Skywalker: Why Rey Didn't Turn Anakin's Lightsaber Yellow
The hypothetical dark side version of Rey uses a hinged double-bladed lightsaber with two unstable red blades, similar to Kylo Ren’s weapon. The simplest explanation for such a weapon is that it was simply a vision and the lightsaber’s unstable blades don’t need to make sense, but there is a way that the weapon could exist without contradicting the internal logic of the Star Wars canon timeline. Kylo
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