Towards the end of the Second Imperial Civil War, the One Sith scientist Vul Isen decided to test his viral spores on the planet Mala, a primitive remote world that was home to an unidentified near-Human species. After using the Imperial fleet to mount a show of force, an unidentified Sith master attacked a local village and killed several people. This brought him in contact with the man who would become Darth Wredd, a skilled swordsman who was strong in the Force. After besting Wredd in combat, the Sith master spared him and brought him aboard the Imperial flagship.
There, Wredd could only watch helpless as the Imperials fired a projectile which delivered the bioweapon into Mala's biosphere. Within minutes, all lifeforms on the entire planet was wiped out and Wredd was the sole surviving member of his species. The blast was so strong that it knocked Mala out of orbit and turned the planet into a rogue world which wandered through the galaxy. Sensing potential in him, the Sith master took Wredd as his apprentice. Wredd's Sith apprenticeship was a brutal experience in which he lost his identity and embraced the dark side of the Force. At an opportune moment, Darth Wredd killed his master and unleashed an insurgency against the One Sith.