The mask represented on the Coppa, the traditional currency of sorcerers, represents that of an Inquisitor. As they do not remove their masks and speak only through telepathic whispers, it is assumed the process of joining the Inquisition involves the fusing of an inquisitor's mask into the skin of the face. As it is, the Inquisition has no ethical qualms using torture as a method for aquiring their desires. While most of the Guild collects riches, the Inquisition trades in a far more sinister brand of currency.
They collect secrets. Beings with knowledge they believe is strategic are of extreme value to them, and through the use of torture and mind-bending magics, they are able to extract the darkest shames and hidden truths from anything. The sadism of the Inquisitors is patient, working little by little, combining a thousand different techniques into a meshed webbing of agony. The brand of magic used by the Inquisition is hard to define, combining telepathy and excruciating mind control, but it is most commonly referred to as the Element of Pain.