The double-bladed lightsaber wielded by Rey's doppelgänger in Star Wars: The Rise of Skywalker resembles the one used by Darth Maul decades earlier, but with some key differences. In her quest to find the Sith planet of Exegol, Rey travels to the ruins of the Death Star II, inside of which she finds a hidden chamber behind a wall of the Emperor's throne room. Before claiming the Sith wayfinder within, she faces a dark side vision much like the one experienced by Luke in the Cave of Evil on Dagobah in The Empire Strikes Back, her foe being a dark reflection of herself.
Rey uses the blue Skywalker lightsaber for most of the sequel trilogy after finding it in Maz's castle on Takodana, only revealing her new yellow-bladed weapon at the close of The Rise of Skywalker. During her Jedi training with Leia, Rey had been considering crafting a hinged double-bladed saber, but seeing a dark culmination of the design in her vision on Kef Bir dissuaded her.
The brief fight scene on the Death Star II gives a clear view of Dark Rey's weapon, and its two red blades immediately invite comparisons to Darth Maul's lightsaber from Star Wars: Episode I - The Phantom Menace. The primary difference is the hinge mechanism at the center of the hilt that can bring the two blades into a close parallel configuration. More subtly, Dark Rey also looked to have made use of damaged Kyber crystals, because her blades had a crackling, unstable quality reminiscent of Kylo Ren's.
After first appearing in The Phantom Menace, the double-bladed lightsaber has since been incorporated into many different eras of the Star Wars universe through video games and television shows and is among the most popular and well-known lightsaber variants. The hinged double-blade lightsaber is relatively recent, first appearing in The Clone Wars in the many hands of Jedi Master Pong Krell before gaining greater exposure in The Rise of Skywalker. As such, there are fewer examples, and it remains seen as an offshoot of the standard double-blade, a variant of a variant, as it were.
Although it draws on many other Star Wars sources, Dark Rey's double-bladed lightsaber in The Rise of Skywalker was likely meant to be an homage to Darth Maul, as his was the only other weapon of that kind to appear in one of the films. However, there are many other points of reference, and given that Dark Rey is a reflection of Rey's anxieties about being pulled toward the dark side, it makes sense that the vision would pay homage to that eldritch tradition and to the history of Force-users as a whole.