The visible face of the Lords Dragon in the Calixis Sector are the Magos Juris, a group of Tech-Priests who have focused themselves solely on preserving the Omnissiah’s will, instead of the never-ending Quest for Knowledge that permeates much of Adeptus Mechanicus culture. The Magos Juris devote themselves fully to their cause, seeking to preserve the Cult of the Machine God from any who threaten it.
Magos Juris are most often involved in tracking down and eliminating tech-heretics, smugglers, and others who have justly earned the wrath of the Adeptus Mechanicus. Unlike the Secutors and the Divine Light of Sollex, however, the Magos Juris are primarily investigative in nature, rather than militant, and amongst their number are many Lexmechanics, Rubricators, and other such scholars who relentlessly sift through data seeking their prey.
The connection between the Magos Juris and the Lords Dragon is kept strictly secret from any outside the Adeptus Mechanicus, and it is common for many, even amongst the vaunted Inquisition, to believe that the Magos Juris are completely independent of any other presumed-mythical agencies.