Trissa lets out a little grin when you give her permission to determine the man's fate. She disentangles herself and approaches the robed monk who is now breathing heavily.
"You may have strayed before," She whispers into his ear, pressing her barely clothed body up against him, "But now that you know the truth, you're certain to be a devoted servant, are you not?"
"Y-yes, Mistress."
"Whom do you serve?"
The man opens his mouth but no words come out. The magic is so thick at this point, you can actually see it. A swirling miasma of blue mindbreaking aura fills the room, flowing in and throughout all its occupants. You begin to hear the whispers of the goddess, promises of power and knowledge forbidden. It is compelling even to your hardened sense, for a mere mortal such as the monk-
"I-I serve the Mother of Magic... I can hear her!"
Trissa strokes his chest teasingly.
"Of course you can. But Mistress Asheroth is right, you haven't shown a depth of dedication one would expect of a true acolyte... I think you'll have to prove yourself before you can truly be embraced by the goddess's faithful. You will serve me and my order in all things, body and soul. When your devotion is unquestionable, we will reexamine your position in the order of the faithful."
The man falls to his knees, kissing your and Trissa's hands before departing without a word. When he leaves, Trissa shudders with pleasure.
"Do you feel it Mistress? This power Hecate bestows upon us? We are truly doing her divine work!"
Trissa's certainly right that. Harnessing this magically charged atmosphere might be difficult, but in doing so, you might be able to convert the entire house in one fell swoop...