Rhelg stands out as a significant world connected to the Sith. During the era of the Galactic Republic, also known as the time, Rhelg faced quarantine alongside planets such as Malachor, Ziost, and Jaguada, with its past and association with the Sith concealed.
Within the current Star Wars canon, the initial reference to Rhelg occurred in the 2019 reference book titled Star Wars: The Rise of Skywalker: The Visual Dictionary, authored by Pablo Hidalgo. Conversely, within the Star Wars Legends timeline, Rhelg made its debut in the comic Tales of the Jedi – The Golden Age of the Sith 4, penned by Kevin J. Anderson, with illustrations by Dario Carrasco, Jr., and released by Dark Horse Comics in 1997.