Naga Sadow was an ancient Sith Lord who, according to the quasi-historical Qel-Droma Epics, led the Sith Empire during the Great Hyperspace War against Empress Teta and the Jedi Order while also triggering the Cron Supernova. The Massassi of Yavin 4 allegedly built the Great Temple under Sadow’s leadership in circa 5000 BBY in his honor, despite his treatment of the Massassi being poor.
A likeness of Sadow was chiseled into the rock walls of the Sith Citadel on the Sith planet Exegol, and First Order Supreme Leader Kylo Ren heard Sadow’s voice among the unintelligible whispers of several Sith Lords while confronting the Dark Lord of the Sith Darth Sidious on Exegol in 35 ABY.
Naga Sadow was an ancient male Sith Lord active by 5000 BBY. According to the quasi-historical Qel-Droma Epics series of poems, Sadow was active thousands of years before the time of Jedi Knight Ulic Qel-Droma. During that period, as the Epics claimed, the Sith Empire conducted an invasion that began the Great Hyperspace War. Empress Teta thus allied herself with the Jedi Order and defeated Sadow’s forces, scattering them across the galaxy. The Qel-Droma Epics also claimed that Naga Sadow triggered stars in the Cron Cluster to form the Cron Supernova, subsequently leaving the nearby Jedi retreat planet Ossus barren and scarred.
The Great Temple on the moon Yavin 4 was alleged to have been built by Massassi warriors under Sadow’s leadership around 5000 BBY. The Massassi admired Sadow as a god despite being poorly treated by him, and the Temple was raised in Sadow’s honor. Archeologists later proposed that the Great Temple may have functioned as a large-scale communications device to contact other Sith Lords throughout the galaxy.