Hades' Helm

Origin
Hades was the god of the underworld in ancient Greek mythology. He, along with his brothers Zeus and Poseidon, fought against and defeated their elders, the Titans. While the earth was province of Gaia, the three brothers split up the other three major areas of the universe, the underworld, air and seas.

Effects
Hades Helm of Darkness, also known as the Cap of Invisibility, turns the person into a shadow, effectively making them invisible. In this state, they can move between shadows with ease. When the person is not invisible, they radiate uncontrollable waves of fear.

One way to get the artifact away from its user is to have someone, preferably one the user owes a debt to, ask to borrow or use the helmet. The user will be unable to resist that person’s request; if they resist, the helmet will only forcibly pull away to the other person.