The Inquisitor is a Civilian unit available through Faith purchase.
Inquisitors were widely utilized throughout Europe as part of a broad effort to eliminate enemies of the Catholic Church. Those branded as heretics by the Inquisition were oftentimes tortured and executed for their alleged crimes, and there was typically little room for defense against the inquisitor's accusations.
Inquisitors are your defense from other religions. They can be placed inside a city to protect it from Missionariesand Prophets trying to spread other religions into that city, or they can remove other religions from only your cities (expending the Inquisitor). This will leave only the followers of your religion in the city, if there were some before the act, and may cause a few other citizens to convert as well.
Note that an Inquisitor doesn't stop religious pressure from converting your citizens.
A useful tactic for Inquisitors is to allow a player to permanently remove a competing religion from the game. This can only be done after capturing the Holy City for the religion. Once it is captured, move the Inquisitor to the city and remove the religion. This will permanently destroy this religion and allow you to replace the religion in other cities without having to worry about the constant pressure from the Holy City.
Unique Unit Replacements
|Battle Priest||The Zapotecs (Cosijoeza)||
|Midew||The Anishinaabe (Pontiac)||