Inquisitors
Inquisitors are religious characters sent to regions with high Heresy by the Pope.
Overview
"An Inquisitor is a special sort of priest, sent by the Catholic church to 'deal with Heresy' when it becomes a serious problem in the Pope's eyes."
- -The Creative Assembly, Official Medieval II: Total War manual
Inquisitors spread the Catholic faith in the current region that they are in, much like Priests, and may denounce Heretics, Witches, Generals, and any characters they suspect of blasphemous behavior, even your Faction Leader! The higher your General's Piety, the more likely he is to survive a Inquisitor's denouncement.
Likewise, the higher an Inquistor's piety level is, the more likely the denounced character is to be found guilty and executed. If there are any Heretics or Witches in your regions, then they will be the Inquisitor's priority.
You may attempt to assassinate Inquisitors, but beware the consequences if you fail! This may include the Papal States' diplomatic relations with you rapidly deteriorating, leading other Catholic factions to declare a Crusade on you.
Inquisitors are less likely to attack your generals and agents if you have an alliance with the pope.
Inquisitors can be ordered to Denounce non-Catholic and non heretic characters, but will not target them automatically.