Prosper's Demon — K.J. Parker

In the pitch dark, witty fantasy novella Prosper's Demon, K. J. Parker deftly creates a world with vivid, unbending rules, seething with demons, broken faith, and worse men.

In a botched demonic extraction, they say the demon feels it ten times worse than the man. But they don't die, and we do. Equilibrium.

The unnamed and morally questionable narrator is an exorcist with great follow-through and few doubts. His methods aren't delicate but they're undeniably effective: he'll get the demon out―he just doesn't particularly care what happens to the person.

Prosper of Schanz is a man of science, determined to raise the world's first philosopher-king, reared according to the purest principles. Too bad he's demonically possessed.