Shortly after this, Tann led a campaign that resulted in both the capture of the Galactic Republic's secret weapon, the Decimator, from the research facilities on Eredenn and the stealing of the activation codes for the machine from Alaris Prime.
Using the weapon, Tann took the world of Sarapin, killing Jedi Knight Jor Drakas and sending shockwaves throughout the entire Republic. To deal with this grave threat, Jedi Master Mace Windu dispatched his new Padawan, Echuu Shen-Jon, Naat Reath, and a battalion of clone troopers to recapture Mount Corvast, the prime energy collection facility on Sarapin. General Shen-Jon was successful in this battle, proving himself to be a tactical planner on par with Tann.
From Sarapin, Shen-Jon led his forces in pursuit of Sev'rance Tann, eventually tracking her to Krant. There, he seized a Trade Federation facility on one of the moons of Krant, which was to be used as a staging ground for his invasion of the planet. However, Naat Reath was captured by Tann, and Shen-Jon began to descend further into the darkness that had been growing within him since the death of Reath's brother.
Pursuing Tann to Krant itself, Shen-Jon fought his way through several large Separatist bases, taking the Decimator facilities and reaching the stronghold of Tann herself. The Separatist general issued an ultimatum—Shen-Jon would fight her alone, or Reath would be terminated. Shen-Jon accepted the challenge and succeeded in defeating Tann, putting an end to the campaign. Shen-Jon bade Reath return to the Jedi High Council, while he himself went into exile.
- Battle of Kaer Orbital Platform
- First Battle of Tatooine
- Battle of Eredenn
- Battle of Alaris Prime
- Battle of Asteroid 426
- First Battle of Sarapin
- Second Battle of Sarapin
- Second Battle of Tatooine
- Battle of Aereen
- Battle of Krant
- The New Essential Chronology (First identified as Hunt for the Decimator)