Genestealer Cult - The Genestealer Curse: Genestealers are vicious and frighteningly intelligent alien lifeforms. They are largely independent, capable of surviving alone for standard centuries. When encountered as part of a brood, however, a gestalt psychic will binds them to one purpose.Originally encountered upon the moons of Ymgarl, long before Hive Fleet Behemoth breached the Imperium, these beasts were once thought to be an entirely separate species to the teeming hordes of the Tyranids. Only when the Ordo Xenos conducted a harrowing program of investigations did they realise the truth -- that the Genestealer was a vanguard creature of the encroaching hive fleets, and that the Ymgarl genus was but one example of the forms it could take.Genestealers are carried from world to world much as a virus is carried from host to host –- unseen and unbidden. Their physiques are so hardy that they can even survive in the cold vacuum of space. There are scattered reports of armies of these xenos creatures emerging from honeycombed asteroids and torn-open ghost ships. The most severe Genestealer infections have been traced to space hulks, vast conglomerate voidships that drift across the galaxy on the etheric tides of the Warp -- on such behemoths Genestealers have been found not in twos and threes, but in their thousands.More commonly, small broods of Genestealers stow away upon the voidcraft of Humanity's endless armadas. Able to fold their gangling physiques into relay pipes and crawlspaces, they can hide in even the smallest shuttles, entering a hibernatory state until they emerge from their sojourn to sow the seeds of destruction anew. Many a bulk transport has arrived at its destination carrying a lethal cargo indeed.When a Genestealer reaches a world ripe for infection, it will clamber into the dark and forgotten spaces of a populous area, lurking unseen as it prepares to spread its influence. As with all their voidborn kind, the Genestealer is inhumanly patient, able to subsist on very little sustenance and to wait for Terran decades if necessary before making its move. Once it is certain of being able to acquire victims whilst remaining undetected, it will begin to abduct them and implant them with its alien blight to make them unwitting hosts of a new generation of terror.A cult can start with but a single organism. Should a lone Genestealer reach an inhabited world, it will immediately go into hiding, emerging only on the blackest of nights. Those who fall prey to the Genestealer's silent ambushes are not torn apart for later consumption, as with most victims of the Tyranid race, but instead put in thrall by its psychically hypnotic gaze.They are then impregnated with a portion of the creature's own biomass, delivered under the skin via a ribbed tube called an ovipositor. This process is known as the "Genestealer's Kiss." The resultant parasitism alters the infected's body until the xenos taint runs throughout. It also alters the mind, forcing the victim through a bioneural psychic connection to revere the Genestealer as a messianic figure, the idol of an obsessive new religion.Whenever a Genestealer implants a victim, a horrific birth will soon follow whenever that individual, whether male or female, breeds with others of its species. The resultant Genestealer Hybrids are grotesque and misshapen creatures that are as varied in form as they are hideous to behold.Certain features are common, such as bulbous craniums and snarling, needle-toothed maws, a pair of extra limbs ending in viciously sharp claws, truncated tail-spikes and mottled, purplish skin. These initial hybrids are known as the First Generation.The hideous hybrids of the First Generation will reproduce with newly-hypnotised members of the cult, who sire young in their turn. This gives rise to the Second Generation. These new creatures are hunched and stooped -- not in the manner of the old or infirm, but more like pressured springs that are ready to explode into sudden movement. These hybrids may have five or even six limbs, but their eyes and mouths are like those of their Human parents, and they can make themselves understood in Low Gothic.Though their minds are still so alien that they defy analysis, the Second Generation is sapient enough to understand its host society. Some are even put to work in the industrial brotherhoods of their kin, their uncanny strength and resilience allowing them to use heavy mining tools and explosives with far more ease than a Human operative.Purestrain Genestealers propagate with a hideous alien fecundity, infecting generations of Human prey until the time is ready to strike. Each new batch of offspring descended from a single Genestealer Patriarch seems more human than the last as the xenos germ-seed is seemingly diluted, but within, the shape of the beast lurks unchanged. At the culmination of the curse's cycle, the original alien nightmares are born anew.As each cycle passes, the hybrid offspring evince fewer and fewer mutations from the human or other host species' genetic baseline. The Third Generation is typified by an upright stance -- though they appear Human from a distance, on closer inspection they have heavily-ridged heads, mauve to violet skin, and may even hide a vestigial limb under their clothes.By the Fourth Generation, the scions of the Genestealer Cult can pass for fully Human, inveigling themselves into positions of power to further the aims of the cult. Leaders of uncanny influence emerge within the hidden cult hierarchy -- psychic magi and charismatic demagogues whose rhetoric inflames the subculture further.Fourth Generation cult members can breed true. They do not give birth to untainted Humans, but instead to Purestrain Genestealers just as alien as the original progenitor of the cult. The parents of these Fifth Generation creatures see them not as the hideous, hissing changelings they truly are, but as soft-skinned Human infants, innocent and sweet. They do everything they can to protect them, even giving their own lives if necessary. By this point, the curse's hold upon the dynasty is complete and the brood cycle begins anew.The Genestealer at the heart of the cult, known as the "Patriarch," has an inherent psychic control over every one of these minions, no matter the generation. The Patriarch unites them in a single sentience -- a gestalt consciousness known as the "Broodmind" akin to the far larger Tyranid Hive Mind.It is this shared sentience that makes the cult so tight-knit and loyal, that gives them uncanny strength and speed in battle, and that seeks to undermine the spiritual sanctity of Mankind. Such xenos cults have thrived in the dark corners of the Imperium longer than any now suspect. On those occasions when they rise up in open rebellion, they can capsize a planet's defences in a matter of solar hours.The cultists of these grand insurgencies have spent their whole lives preparing for the day of the final conquest. Generation after generation have been bred in secrecy, cycle after cycle bearing nauseating fruit. The infected have spread the curse to others, and to their children, who in turn have infected more. Like a living virus, they breed exponentially, their numbers swelling until the rulers of the society's underworld are strong enough to seize the entire host planet.Though the later generations of each cycle have the appearance of common men and women, inside they are xenos through and through. Their allegiance is owed only to the organisms that brought the Genestealer Curse to their world, and the hybrids of their hidden kindred. Their Patriarch, starborne and inhuman, squats at the centre of a web of influence that expands until it covers the entire world. Every soul in the cult is mindlessly obedient to this repulsive creature, and would give their lives to save it.Once the cult is fully mature, it seeks to propagate once more. Its leaders carefully send selected Purestrains on long journeys to locate new feeding grounds, there to begin the whole hellish process over again.