But he is denied a wavier and whence the adventure begins.
de Camp's one central grace for me is he writes about people. His villians will look at you and say, "Me, a villian? But you, dear sir, are far more a villian!" And they mean it, spouting viewpoints which are (in the villian's sense) perfectly logical (if not exactly moral). Culture clash is often the center of his stories. Take a demon skilled in logic and reason and throw him in with barbaric humans and you wind up with non stop exasperation and amazement at the duplicity involved. As Zdim points out, 'feindishly clever' is quiet a strange racial tag for the incessantly cunning and devious humans to come up with!
"I endeavor to give satisfaction," is perhaps the exasperated catch phrase of the de Camp books.