Mutants - Psychic Mutants: There are many types of mutations and some affect the mind rather than the physical body, producing individuals with the ability to access the psychic energy of the Immaterium and use it to reshape the physical world. These psychic individuals always run the risk of becoming a host for the malevolent entities dubbed "Daemons" that inhabit the Warp.These mutants are generally referred to as "psykers" in Low Gothic and they are among the most feared of Human mutants. Humanity is not a naturally psychic species like the Aeldari or the Orks and the ratio of physical to mental mutation among Humans is approximately 1000:1, or 1000 physically mutated individuals for every one born with psychic abilities.Psykers are not left to live out their existence like most mutants but are taken from their homeworlds by the Imperium as part of the Great Tithe in the Inquisition's Black Ships to be trained by the Adeptus Astra Telepathica since they are considered far too dangerous to be allowed to exercise their abilities without proper Imperial conditioning.The training of Sanctioned Psykers by the Imperium allows them to be used in battle with the Astra Militarum, to fuel the power of the Astronomican by sacrificing their lives to help the Emperor maintain that great telepathic beacon of interstellar travel or to serve in the choirs of astropaths who telepathically communicate between distant worlds.They are tested for aptitude by the Adeptus Astra Telepathica and the dangerously unstable or those deemed too mentally or spiritually weak to protect their minds from Daemonic possession are executed immediately. The survivors are taken in the infamous Black Ships of the Adeptus Astra Telepathica to be transported to Terra for their training.Some will eventually serve in the roles mentioned above or are even assigned to the service of the Astra Militarum. The luckiest psykers may be discovered by and adopted into the Chapters of the Space Marines before being handed over to the Adeptus Astra Telepathica where they become Librarians. Some may even eventually be accepted into the retinue of an Inquisitor as an Acolyte and eventual Throne Agent, if they do not eventually rise to become Inquistors themselves.Psykers wield many and various powers, including the ability to gaze into the future, to shoot lightning out of their hands, to control the actions and minds of others and, most dangerously, to open portals from realspace into the Warp.The Warp is inhabited by many horrible and powerful entities such as the Chaos Daemons and the Enslavers. Psykers are like lights in a dark cave to these entities who can see them when they use their power and who desire an entry into the physical universe where they can unleash great mayhem among mortals.Therefore, whenever psykers use their powers they are at risk of possession by these Warp entities. A possessed psyker acts as a portal for Daemons into the material world and may become a horrific Daemonhost themselves, spreading the corruption of Chaos wherever they go. As more Daemons come through the portal, they tear open the gateway further, slowly pulling a portion of the physical world into the Immaterium until reality begins to warp and reform under the strain of Chaos.Untrained psykers have no hope of survival against such an attack, and it was the occurrence of such tragedies when uncontrolled Human psykers first began to appear at the end of the Age of Technology that helped bring on the terrible destruction that consumed Human space during the Age of Strife.Not all who are touched by Chaos sought the attention willingly. The raw stuff of Chaos permeates the fabric of reality, warping and twisting it on a whim. Inquisitors and others who deliver Imperial justice hunt down and kill mutants as part of their duty to keep the foul taint of Chaos from destroying all that their God-Emperor has built.Even being a loyal citizen does not spare these mutated people from the purging fires of judgement. This can easily be seen as a betrayal to the mutants. With nowhere else to turn, they will seek each other out and devote themselves to the Dark Gods.