Although Star Wars: The Last Jedi, JJ Abrams' sequel and close to the Skywalker saga introduces a deadly Sith assassin who was deeply loyal to the resurrected Emperor.
When Rey, Finn, Poe, Chewbacca, and C-3PO go to Pasaana to track down the Sith wayfinder, they meet Lando Calrissian who informs them that a Jedi hunter had possession of the wayfinder. Later, when Kylo Ren reveals that Rey's parents died trying to protect her, he also reveals that the same Sith assassin was responsible for the deaths of Rey's parents, Ochi of Bestoon.
Ochi of Bestoon has a history of violence stretching back to the Clone Wars when, for reasons unknown, he took to slaying of the Jedi Order. This vehemence grew into a fanaticism for all aspects of the dark side, academic and practical, in spite of his lack of Force sensitivity. Drawn naturally to the Sith Eternal in the New Republic Era, Ochi was one of few citizens of the galaxy who knew of the survival of Darth Sidious after the Battle of Endor. It was in service to this revenant master that Ochi killed Rey's parents in his search for the young heir to the Sith throne. In committing these murders, he used a blade inscribed with Sith runes naming the location of the Sith wayfinder that led to Exegol.
The reputation of this dagger seems to have preceded Ochi, as Luke Skywalker, in his quest to find Return of the Jedi and The Force Awakens, Skywalker and Lando Calrissian successfully tracked him to Pasaana, but the trail went cold from there. It was only many years later, when Rey, Finn, Poe, and company were seeking the same goal, that the remains of the vicious assassin were discovered in a system of caves beneath the planet's desert.
Despite his very abbreviated appearance in The Rise of Skywalker, Ochi represents one of the most concrete attempts in the current Star Wars canon to look at how the dark side influences people without Force sensitivity. As the series expands beyond the story of the Skywalker family, a broader view of the universe will necessarily include unorthodox approaches to the Force, and while this does include heroics of the sort seen in media like Jedi: Fallen Order, it also entails supernaturally malicious villains like Ochi of Bestoon.
