A man-made virus, Vira606, was created to serve the purposes of the Imperial Security Bureau. The virus invariably led to death, and while it could not spread from person to person, no treatment existed to reverse its effects. However, its deadly effects could be suppressed through consistent doses of a specially formulated serum.
Vocis Kenit intentionally exposed the members of the Solar Terrors to Vira606, controlling their actions by providing the serum in exchange for their completion of assigned duties.