Sleeper Agent

Sleeper agent:

A usually placid or supposed regular headmate who, when a specific headmate (or person outside of the system) is hurt or negatively impacted, will forget or throw aside all sense of morals to protect them. The term is different from a swordsperson in the sense that it's not required for their role to protect, take care of or help anyone until said person(s) are hurt.

While protecting someone, they will likely become significantly malicious to anyone besides the person(s) they are protecting. They may also change their form when they are "activated".

The term was taken from sleeper agents ; agents who live normal lives as law-abiding citizens in target countries/organizations until they are "activated" as spies with a prearranged signal.

Related Terms
A sleeper agent is, essentially, a more specific term for a kind of swordsperson. A sleeper agent is a swordsperson, but not every swordsperson is a sleeper agent. The term can be used as a stand-alone role if the person feels it is.

Sleeper agents can (but don't have to) consider themselves two sides of the same coin, being one person or a certain way unless flipped (two-coined).

History
The term was coined by aaabe& and Villa from The Infinite Ikea. The idea was started by aaabe& when he couldn't find the term he was looking for, in which Villa showed interest due to the term suiting him. The name for the term, and the description, were given by Villa, with aaabe& altering and adding onto the description. All of this took place in a Discord server for plurality.