Rey's upcoming Jedi Order film will require a fresh antagonist, and given the absence of the Sith, a species from the Star Wars Legends universe could serve as a fitting substitute.
Star Wars is no stranger to horror, from Night Troopers appearing in Ahsoka Season 1, to deadly Imperials with a taste of flesh being introduced in the Death Troopers novel and even the Ewok Hunt game mode in DICE's Star Wars Battlefront 2.