A "Psyker" is a term used in the Warhammer 40,000 universe to describe individuals who possess psychic abilities. These powers allow them to manipulate the warp, a parallel dimension that fuels psychic phenomena. Psykers can perform various feats, such as telepathy, telekinesis, and even powerful offensive attacks, making them valuable assets in battle. Psykers are often associated with the Imperium of Man, where they serve as Astropaths for communication or as Sanctioned Psykers in the military. However, their abilities come with risks, as they can attract the attention of malevolent entities from the warp, leading to potential corruption or madness.