In 3756 BBY, the Human Jedi Master Barel Ovair and his Nautolan Padawan, Eison Gynt, set out on a mission to the fourth moon of the planet Yavin. The two had spent much time together exploring locations throughout the galaxy that were strong in the Force and planned to search the Massassi Temples on Yavin 4 and delve into the tomb of the ancient Sith Lord Naga Sadow. Ovair, however, was actually a servant of the exiled Sith Empire, on a mission to destroy the spirits of long-dead Sith who might challenge the power of the Sith Emperor upon his return to known space.
After arriving on the moon, Ovair and Gynt were attacked by Sadow's surviving Massassi warriors. Defeated, they were forced into the heart of Sadow's tomb, where they were overcome by the Sith Lord's still-lingering dark energies. Ovair was unable to accomplish his objective and so abandoned Gynt there. Weeks later, he returned to the Jedi Temple on the planet Coruscant, claiming Gynt had been killed. However, the young Nautolan survived, only to be possessed by Sadow's spirit and killed years later by Ovair.
Naga Sadow on Yavin 4
Following the defeat of the Sith Empire at the conclusion of the Great Hyperspace War in 5000 BBY, Dark Lord of the Sith Naga Sadow fled the forces of the Jedi Order and Galactic Republic and sought refuge on the fourth moon of the Outer Rim world of Yavin. On the moon, Sadow's Massassi servants constructed massive temples in the Dark Lord's honor, one of which eventually served as his tomb. Meanwhile, other remnants of Sadow's defeated Empire committed themselves to self-imposed exile in the Unknown Regions, where they worked to forge a new Imperial regime led by one of the final living Dark Lords.
This Dark Lord, known only as the Sith Emperor, began preparing his Sith for a renewed conflict against the Republic in retribution for the defeat they suffered during the Great Hyperspace War. To that end, the Emperor dispatched spies throughout the galaxy to infiltrate the Republic and weaken it from within. Several of these spies were members of the Ovair family—Sith who were assigned to masquerade as Jedi and use their position to gain access to the burial grounds of dead Sith Lords. The Ovairs' mission was to destroy the spirits of these Sith to prevent them from challenging the Sith Emperor's power upon his return to the known galaxy.
Barel Ovair, a third-generation Sith spy, took up the work of his father and grandfather under the guise of a Jedi Master and scholar. Alongside his Padawan, the Nautolan Eison Gynt, Ovair traveled the cosmos in search of Sith spirits. Gynt was unaware of his Master's mission, as Ovair had told both his apprentice and the Jedi Council that the purpose of their travels was to investigate locations strong in the Force. The two undertook increasingly daring missions until 3756 BBY when the elder Jedi decided to take his apprentice to Yavin 4 to explore the Massassi Temples. In reality, however, he planned to infiltrate the ancient crypt of Naga Sadow and destroy the residual traces of the Dark Lord's spirit.
Ovair and Gynt within Sadow's tomb
Upon reaching the moon, the two Jedi made their way to the massive temple that housed the Dark Lord's body. Before entering the great structure, they were set upon by hoards of Massassi warriors emerging from the surrounding jungle. These Massassi had survived the centuries since Sadow's death and remained to guard their master's tomb but were twisted by Sadow's experimentation on them many years before and were now mutated wielders of the dark side of the Force. Ovair and Gynt battled into the temple, where they were attacked by even more of the alien guards.
Although the two fought determinedly against the Massassi, they were eventually defeated and forced to retreat into the heart of the temple, where Sadow's sarcophagus was kept. There, they experienced the power of the dark side that still emanated from the Dark Lord's body. However, Ovair failed to destroy Sadow's spirit and fled the moon, abandoning his apprentice within the tomb.
Master Ovair returned to Coruscant.
Several weeks after the mission, Ovair reappeared at the Jedi Temple on the planet Coruscant. The false Jedi Master appeared heavily wounded and partially insane due to the ordeal and received intensive care. His recovery process dragged on for an extended period of time, but Ovair eventually found himself able to make a report of the incident on Yavin 4. In an address to the Galactic Senate of the Republic, Ovair explained the horrors he had faced on the moon and claimed that Eison Gynt had been killed during their captivity within the tomb. Ovair resumed his post as a Jedi, but several years later, Gynt reappeared on Coruscant, possessed by the spirit of Naga Sadow. He intended to kill Ovair in retribution for his attempt at destroying the Dark Lord's spirit on Yavin 4.
Gynt attacked his former Master, but Ovair prevailed in the ensuing duel, killing the Padawan and neutralizing Sadow's specter, thereby fulfilling the edict given to him by the Sith Emperor. Around a hundred years later, in the aftermath of the Sith's successful campaign against the Republic and the Jedi, Jedi historian Gnost-Dural investigated the events surrounding the mission to Yavin 4. Gnost-Dural's research revealed Ovair's true allegiances and the purposes for his travels, as well as his family heritage and their contribution to the Empire's war against the Republic. Satele Shan, the Jedi Grand Master of the era, concurred with Gnost-Dural's research and included notes on the mission to Yavin 4 in a wartime journal submitted to the Jedi Archives on the planet Tython.
The mission to Yavin 4 was first seen in the seventh entry of the Galactic Timeline, an online video series created to elaborate upon the background for the LucasArts/BioWare video game Star Wars: The Old Republic. The entry, titled "Peace for the Republic?," was published on April 16, 2010, on The Old Republics official website and is narrated by actor Lance Henriksen in his vocal portrayal of Jedi Master Gnost-Dural. "Peace for the Republic?" presents an inconsistency regarding the destruction of Naga Sadow's spirit. Although the 2008 reference book The Complete Star Wars Encyclopedia had previously claimed that the Dark Lord Freedon Nadd destroyed Sadow's spirit in 4400 BBY, the Timeline indicates that Sadow's spirit was still lingering on Yavin 4 around 644 years later.