Both the aforementioned Reddit thread and a post by Michael J. Miller on the blog My Comic Relief highlight the same idea — that perhaps the biggest sign of Rey’s Sith leaning is her use of the Force to save Kylo Ren (Adam Driver) from the brink of death during “The Rise of Skywalker.” Anakin’s story arc in the prequel trilogy positions bringing someone back from the dead as the ultimate Sith superpower, so the fact that Rey manifests this ability is arguably the clearest sign of all that the dark side is her destiny.
Of course, if Rey does turn out to be evil in the next Star Wars film, the significance of her choosing the Skywalker name over her Palpatine birthright would be undermined. One way she could still be a Sith without diluting her character arc, however, would be to somehow redeem the Sith or put a more nuanced spin on the dark side, as was once the case in the old Expanded Universe. Plenty of Star Wars works — like the video game “Star Wars Knights of the Old Republic II,” for instance — characterize the Jedi and the Sith in shades of gray rather than strictly good and evil. If Rey can accept her affinity for the dark side and still do good in the world, she would ultimately be doing her chosen Skywalker name justice in an altogether unexpected manner.
Of course, given all the Force dyad hijinks, this is still just a theory.
