The Devil Speaks II.
Since then, I have read about Asmodeus in Alan Moore's Jerusalem (see here) and am currently reading Elliot S. Maggin's Superman: Miracle Monday in which Samael sends the curiously named demon, C.W. Saturn, to destroy Superman, not physically but morally.
It was because the Adversary had spoken in Poul Anderson's Operation Chaos that we listed these other cases of the Devil speaking in literature and fiction.
We have also listed human villains. Stirling's are the most evil, I think. Anderson's Aycharaych and Merau Varagan are (a) different from each other and (b) both psychologically interesting. There are many versions of Lex Luthor. Maggin's version has to express himself in ingenious, elaborate, expensive, flamboyant deceptions. His motivation does not seem to be evil and I do not expect him to seek common cause with C.W. Saturn but what do I know of the mind of a villain?
As Hamlet said:
"One may smile and smile and be a villain..." (see here)