Ordo Sicarius
The Ordo Sicarius, who - following the nicknaming conventions of the other Orders - would presumably be the Assassinhunters, are an Order of the Inquisition formed after the Age of Apostasy and the Wars of Vindication which threw the Officio Assassinorium into chaos (small "C"); during the reformation of the Officio, Inquisitor Jaeger requested that an Order of the Inquisition was formed to monitor the Assassins. Thus was formed the Ordo Sicarius, to root out any corruption within the Office of Assassins.
As the Assassinorium works secretively, each of the Assassin Temples contains a number of Assassin-Inquisitors to monitor them from within. One has to wonder how an Inquisitor Eversor would work...
The Ordo Sicarius has successfully uncovered and prevented two assassination attempts on the High Lords of Terra; considering that each assassination requires a two-thirds vote from the High Lords, the fact that they needed prevention is... odd.
