We swears to serve the master of the Precious!
~ Gollum, swearing to be Frodo's servant.

Villains who served as some kind of subordinate to the hero. At first, they may appear loyal to the hero and exercise his/her duties, but later reveal their motives and betray the hero.

In some cases, the villain may still act as some kind of subordinate to the hero, executing their evil plot without the hero knowing or affecting their ties to the hero.

Do not include villains who were apprentices to the hero or a subordinate due to familial hierarchy (e.g. Son of Hero).