What is a Machiavellian villain?

A Machiavellian villain is a character portrayed in literature who is in a sense a "puppet master". He uses other "tool villains" in order to get what he desires. A Machiavellian villain always operates in secrecy, concealing his true intentions from everyone.

The term is based off the philosophies of Machiavelli, a political philosopher who wrote The Prince- a treatise that outlines the most effective way for a king to govern.