“Demon: I'm not Regan.
Father Karras: Well, then let's introduce ourselves. I'm Damien Karras.
Demon: And I'm the Devil. Now kindly undo these straps.
Father Karras: If you're the Devil, why not make the straps disappear?
Demon: That's much too vulgar a display of power, Karras.”
More from William Peter Blatty
“Let Jesus fuck you, let Jesus fuck you. Let him fuck you.”
“You're going to die up there.”
“Especially important is the warning to avoid conversations with the demon. We may ask what…”
“Your mother sucks cocks in Hell, Karras, you faithless slime.”