A faction within the Roman Catholic Church who exist to pursue and fight supernaturals. They are a major threat to every group of supernaturals because of their extensive knowledge, training, equipment, preparation and fanatical zeal.

The Society of St. Gilles fully believes that the Apocalypse is drawing near and that all supernaturals, willing or not, are part of the army of the Antichrist. As self-appointed soldiers of Christ, they believe it is their divine duty to slay or otherwise neutralize as many supernatural threats to Christianity as possible before Christ returns to the world.

The Society of St. Gilles claims that their ideological roots lie in the Michaelites, a secret order founded by a converted Roman soldier that was dedicated on protecting the early Christians that hid in the Roman catacombs from the monsters that lurked within.

Their official formation, however, came with the advent of Antoine de Castelnau, a French Dominican who was granted special dispensation by Pope Gregory IX in 1231 to combat supernatural evil. Under Antoine's guidance, the society grew, encountering several strange supernatural creatures that abused and toyed with humanity for their own amusement. Although the Society was also pursuing "regular" heretics, like the Albigensians, they also attacked supernaturals wherever they could find them. Among their victims, accusations and imputations flew around, as each group suspected their rivals to pull the strings behind the new threat, unaccustomed to the fact that humans had began to realize their presence in their midsts. When Innocent VIII published the Summis Desiderantis Affectibu in 1484, the Society had reached its peak, raging across Europe in a merciless crusade against the powers in the shadows. However, as the methods of detecting supernaturals were far from rarefied, countless innocents burned alongside mages and vampires. It was during these times that the Society were turned into a secret society within the Church, out of fear of infiltration. The Testament of Castelnau became the canon for the society, who was granted the Monasterio di San Michele in Rome as headquarters.

In 1658, the Society faced its first schism. Michael Pilitus, a Venetian Franciscan, was charged with treason, as he had been found consorting with the enemy. Pilitus tried to persuade his officials that some of the supernaturals were able to overcome their inherent evil nature by honest remorse and accused the Society of pride for judging who among the remorseful had the right to live. Pilitus was sentenced to death and the Venetian Decree was commissioned to further define the orthodoxy of the Society. Inadvertently, the Franciscan's martyrdom by fire created the splinter faction known as the Order of St. Pilitus.

Following the 18th century, the Society waned in both influence and power, as the Catholic Church had other problems to deal with. Some Inquisitors even considered breaking away from the Vatican, but realized that they depended too heavily on financial support from the Church. The Parisian Cenaculum even had to be disbanded due to troubles during the Revolution and the membership dropped to 50 active Inquisitors for all Church territories.

In the 19th century, the Society slightly recuperated. Pius X reorganized the Society in 1908 and officially released them from service to the catholic Church, allowing them to act more freely. Now unconcerned with doctrinal issues, the Society has dedicated its whole power to cleanse the world of what they believe to be the servants of the Adversary and prepare the world for the Parousia.

The Society of St. Gilles is led by the Inquisitor-General, who has absolute lifetime authority over its members and resides in Rome near the Vatican. Beneath him serve the Provincials, who are chosen by the General and assigned to specific geographical regions, where they supervise and coordinate the local Cenacula, the cells of activity. Most Provincials refrain from joining their brothers in the field, instead acting as advisers, mentors or scholars. All Provincials meet annually in Rome to discuss the previous year's activities and plan for the next year. Even prominent witch-hunters outside the Society are invited to these Councils.

The contacts of the Provincials are the Abbés, who are responsible for maintaining and stewarding their Cenaculum. They are aided by the Censors, who are part of the Office of the Censor, who ensure doctrinal orthodoxy and rout out infiltrators, but also ensure that individual Inquisitors do not abuse their powers or Society funds. Councillors are Inquisitors that have proved themselves as experienced and outstanding warriors against the forces of evil and are given this honor-title to reflect their progress. The ordinary Inquisitor usually holds the rank of Tertiary, pointing him out as one who has passed his novitiate. Inquisitors usually work together in cenacles, centered around their Cenaculum.

Below the Tertiaries are the Novices, who are educated over the various supernatural creatures that roam the night. Many Novices come from clerical ranks, but there is also a great population of laypersons, who have not been ordained as priests, as well as, in modern days, several women that have been included into the Society.