Genestealer Cult - The Hive Fleet Descends: In the subculture of the Genestealer Cult, every action, every uttered phrase, is another step towards a final destiny so apocalyptic it will devour friend and foe alike. Should the cultists achieve their ghastly agendas, each world they have worked so painstakingly to conquer will be stripped bare of everything, even its atmosphere, by their ultimate masters -- the Tyranids.As a cult pushes its tendrils ever further into its host civilisation, it prepares for the day of its great ascension. Though it may be solar decades, even Terran centuries in coming, sooner or later a psychic shadow will fall upon the star system in which the cult has spread. This is the Shadow in the Warp, the first sign of the utter despair to come.At first, the strange penumbra of this psychic influence sends soothsayers mad and inspires wild panic in those who channel the energies of the Warp. The Astronomican at first becomes dim, then shrouded completely by the psychic miasma crawling across the stars, cutting the star system off from the rest of the Imperium so it becomes all but impossible to send reinforcements.Only then does the source of the threat emerge from the darkness. Starlight glints from a flotilla of celestial bodies, visible as a shoal of dots in the night sky. While these bodies may appear beautiful at first, their surpassing ugliness becomes more evident as they draw close. This is a bio-fleet of the Tyranid race, and it has come not to enlighten, but to devour.The cult sees the arrival of this impossible menace as the long-awaited fulfilment of their prophecies. They believe the Patriarch's kin, unfettered by Humanity's failings, are here to elevate the faithful and lift them into the light forever. The skies cloud over, thickening with xenos Mycetic Spores as the Hive Fleet prepares the cult's world for consumption.Enraptured, the cult's true believers tell each other that it is always darkest before the dawn. Celebrations and warlike shouts ring through the streets as their devotional frenzy reaches new heights. When the Tyrannocytes rain from the sky like fleshy meteors, the cultists wave their banners high, hoping to attract the attention of the angelic host.As the giant brood-sacs of the bio-ships split open to disgorge shrieking, blade-limbed war-beasts, a seed of doubt worms into the minds of the cultists. Still, their belief in the notion of star-borne saviours is so ingrained they keep fighting against the wider populace. The Tyranid invaders mass together into a tide of chitin and fang, surging over the lands to cut down or consume the indigenous populations.With the Hive Mind guiding each brood, the Tyranid hordes do not see the cultists as prey; in fact they are ignored at first by the synapse creatures coordinating the attack. For a short and blissful period, cultist and Tyranid fight on the same side.Once their adversaries have been slain, the cultists become eager to embrace their distant relatives in celebration, jubilant that their star-spanning family is at last complete. They walk forward, arms wide, into the seething avalanche of weapon-forms. They too are torn limb from limb. Only then does the true magnitude of the cult's folly hit home. The mood of the cult swiftly changes from dogged loyalty to panic.The final revelation comes both from within the cult and without. Those the cultists once adored turn upon them in the worst of all possible betrayals; any who seek succour from the Patriarch instead go to their doom. With its sentience subsumed by the greater Hive Mind, the creature becomes just another Tyranid, another nameless cell in the void-crossing super-organism that wants nothing less than to devour the galaxy.As soon as the planet's defenders are overcome, the Patriarch and its brood will attack their own, wicked claws punching into close advisors and trusted minions, who die choking on their own disbelief. Those Purestrain Genestealers spawned upon the host planet attack their devoted fourth generation parents without hesitation, slaughtering them in a flurry of talons and snapping mouths. Those of the cult who somehow survive this grim twist of fate flee as best they can, but they do not get far.The hail of Tyranid spores intensifies, and the planet itself is altered on a molecular level, becoming a noxious hell. Alongside the bodies of the wider populace, the corpses of the cultists are devoured and regurgitated into the acidic digestion pools that bubble upon its surface. There, they are dissolved into a sickening gruel, raw biomass that is sucked up by ribbed Capillary Towers into the bio-ships high above. So it is that the host population and the cult's parasitic reflection are made whole at last, their bodies mingled in the final act of this apocalyptic tragedy.Not all those Genestealer Cults spawned across the galaxy meet a grisly end, consumed by the maws of the terrifying creatures they worship. Some rise to prominence, subconsciously sending out a psychic aura that attracts a Tyranid biofleet -- only for that fleet to be flung into nothingness by a Warp Storm, engaged in battle by a conventional fleet, or consumed by a violent celestial phenomenon such as a supernova.These cults go on to propagate again and again, their brood cycles consuming ever more of the host planet until it is fully claimed by the Patriarch and its kin. Such planets become the cores of a spreading network of infestations that can cover several star systems or even span an entire sector, preparing the way for a destiny that will never come.In time, they may attract another Hive Fleet towards them -- though until that day they are free to reign supreme over their host domain.