The Opus are man-made anti-Valentine units which were constructed following the Baptisma 13 incident in order to counter future Valentine attacks. Development of the Opus was instructed by the Sanctus Populi and championed by its leader Maximus Ariels, with the United Kingdom of Illyria leading development.
When the Cradle appears near the Black Sea on October 29th 2187, the Opus units that are present survive the sphere that expands from the Cradle before it disappears (actually an intrusion of space from the Backyard). Research by Dr. Paradigm reveals the Opus are in fact Gears, a fact which shocks Leo Whitefang and President Vernon when Paradigm reveals it to them. During the final phases of the Conclave's plan, they use Justice's ability to command Gears to turn the Opus against the defenders of Illyria Castle.
- ↑ Guilty Gear Xrd -SIGN- Story Mode, Chapter 1
- ↑ Guilty Gear Xrd -SIGN- Story Mode, Chapter 5
- ↑ Guilty Gear Xrd -SIGN- Story Mode, Chapter 9