Albion researched Vulgus firearms in order to develop new weapons. This firearm was also taken from the Vulgus for research purposes.
During research, it was discovered that this firearm once belonged to Commander Greg of the Legion of Darkness. Even though it has a specialized bullet made specifically for this weapon, they were able to recognize it thanks to the meticulous records of the Recon Squad that tracked down enemy Commanders and thanks to the records of the Colon Special Forces. According to those records, Greg worked his way up from a War-Slave to a Commander. This was very rare, even for the Vulgus. Perhaps that is the reason this weapon is called "Greg's Reversed Fate."
The Magisters' goal was to convert the firearm's Vulgus ammunition into common Albion ammunition. After much research, they were successful in modifying the ammunition's specifications so that it could be distributed using human technology without sacrificing performance.