During the Great Galactic War, both the Sith Empire and the Galactic Republic launched a galaxy-wide search for the renegade Sith apprentice known as Exal Kressh. Kressh, a Sith follower and student of the Sith Emperor, defected from the Empire when she discovered her Mentor intended to use her as the initial member of his "Children"—a group of beings completely controlled by the will and abilities of the Emperor. After realizing the Emperor's Children were intended to be mere puppets of his Force spirit and instruments for achieving eternal life, Kressh fled the Empire in 3678 BBY and immediately started working to sabotage the Emperor's scheme to create more Children using Sith sorcery. However, as Kressh began providing Imperial Military secrets to the Republic Strategic Information Service, the Empire's Dark Council tasked the disgraced Sith apprentice Teneb Kel with tracking down and killing Kressh. Simultaneously, the High Council of the Jedi Order, having observed Kressh's leaked data being distributed to the Republic Navy, commanded that the apparent Sith defector be located to verify her identity and the truthfulness of her information.
Knowing the Emperor's mind was still linked to her own, Kressh looked for seclusion and protection in the void above Lenico IV, the world where she had uncovered her Master's secret during her training. Hoping the memories of Lenico would obscure her location from the Emperor, Kressh entered stasis aboard Lenico Colony Blue as she awaited the Republic Navy to act on her leaks and prepare an offensive against the Sith sacred world of Korriban. While this strategy was effective for a period, Kressh was eventually discovered by Teneb Kel and his servant Maggot, as well as her Jedi pursuers, Master Jerbhen Hulis and his Padawan. Kel was the first to find Kressh, and he immediately engaged her in a devastating battle that led to the destruction of the colony space station. Although the rogue Sith decisively defeated her opponent, Kel managed to escape with Maggot and was stranded on the surface of Lenico IV, along with the Jedi and numerous civilian survivors from Lenico Colony Blue. After almost perishing on the Ash Plains of Lenico IV, Kel experienced a Force induced premonition that allowed him to understand Kressh's past and the Emperor's clandestine Children collective.
At the same time, Kressh was en route to Korriban, where she intended to use the attacking Republic Military as a smokescreen to infiltrate the Sith Academy. Inside, she hoped to locate and eliminate the Emperor's Children, who were being prepared for a ritual possession. With verification of Kressh's arrival on the planet, a Republic armada invaded the Horuset system and launched an assault on Korriban itself. As Republic strike teams and Jedi landed in the Valley of the Dark Lords and stormed the Academy, Kressh navigated the maze of tombs beneath the valley to secretly access the Emperor's ritual chambers. She was ultimately discovered and confronted by Teneb Kel, who had escaped Lenico IV and was determined to fulfill his mission. Following an intense fight, Kel struck down Kressh but was also forced to sacrifice his companion, Maggot. Due to Kel's success in hunting down Kressh, the Empire managed to repel the Republic assault, and the Emperor's "Children" project continued without interruption. The young Sith apprentice was granted the title of Darth Thanton for his accomplishments, while the Empire proceeded to erase the Kressh name from the records.