energumen

Isaac closed his eyes and muttered, “By the power that is within me, in the name of the Lord Jesus, I ask, Lord, I ask that this wicked spirit be cast out, that Satan’s work be confounded, that this unfortunate Africk energumen be freed from the shackles of diabolatry as he was of slavery.”

Colin is a sort of freelance philosophical energumen, who, upon receiving several cryptic typed messages, makes them the subject of an obsessive study.

And Pascale Ogier was a young energumen of the new Paris night life.

Energumen, en-er-gū′men, n. one possessed: a demoniac.

"This, then, is that energumen whom we are so frightened of in the provinces!" exclaimed our friend.