Taint

Taint was a Force power that allowed a Force-user to taint an object or person, such as it was the case after, while seeking revenge, Jedi Grand Master Luke Skywalker fought Dark Lady of the Sith Lumiya and beheaded her leading to the dark side of the Force, thus causing Force-users connected to the light side to feel great pain. The object or person would radiate the dark side to any Force-sensitives. If the being was neither of the dark side, or light side, and they came into contact with the object then it would cause them to suffer a stun effect. Because of the nature of this power, it would cause beings to be seduced by the dark side.

Text and facts from the “Taint” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.