Hang on, Marcus, you think you have an inkling on this- due to having checked the Cult's background before you came, and having a high Savoir-Faire score. It is something to do with their religion- a force of venegance and retribution?
"The one who called himself an Emissary of the Machine God did not come alone- he brought the Dark Thrael with him. It is unstoppable, inconceivable... and all who face it shall perish. It is the Avatar of the Machine God."