Amulet that deceives its master

The amulet is a block of amber hanging by two thin chains of metal. If one were to look into the amber, they would feel as if they see something but cannot tell exactly what. It is a sentient item that chooses one master and eventually betrays them, it has telepathy, telekinesis and the ability to slowly drain the wearer of their life force.

Notes: Bonus: Ability Checks