Prophaniti

From Lexicanum

Prophaniti was a Daemon trapped into into a human host by Inquisitor Quixos. Quixos was never able to determine the demon's true name, resulting in the name he gave it (something of a play on the word "profanity", which is ironically appropriate). Along with Cherubael, Prophaniti served as part of Quixos' "entourage".

In 343.M41, while on the hunt for Quixos, Inquisitor Gregor Eisenhorn confronted Prophaniti in combat; the two had met in battle once before, the Daemonhost commenting on the weakness of the Inquisitor's weapons despite the addition of pentagrammic wards. Utilizing his runestaff, Eisenhorn channelled enough power into the daemon to not only banish it, but completely annihilate it.

Source

• The Eisenhorn Trilogy by Dan Abnett