Genestealer Cult - Major Cults: Bladed Cog - The slave revolt of the planet Feinminster Gamma eventually proved more powerful than the Cult Mechanicus crusade that surged across its surface. The army of Magos Dominus Ovid Thrensiom had arrived in force seeking a rich harvest of bio-electricty from the planet's living population. The atmosphere of oppression and paranoia that resulted was fertile ground for the spread of an underground religion. When a Purestrain Genestealer was unwittingly borne to the planet's surface by the freighter Redspark, a widespread cult was soon to follow. The xenoform was seen as proof that there were other worlds beyond the clouds and that salvation could be found in its worship. When Thrensiom was overthrown, the broodkin of the Bladed Cog swapped one set of cruel masters for another, though the latter brotherhood are infinitely worse. Infesting the forge-clades of Feinminster Gamma now is the cult of the Bladed Cog. The code-brands and Electoos with which the planet's Tech-priest overseers mark their citizen workers are often altered in illicit inker-dens. The Omnissiah's Cog Mechanicum is changed and adapted to better resemble the jag-spined emblem with which the creed marks out its faithful. Slogan-tattoos are also common, worn across the collarbones or spine.Hivecult - The Hivecult is a prime example of a Genestealer infection that has spread like wildfire across a densely populated Imperial world. The planet of New Gidlam has thirteen hive cities upon its pollution-blasted surface, each harbouring tens of billions of souls. All bar one is besieged from below by the same cult. Though the cult's emergence began in each hive with a spate of ritual killings, the violence soon blossomed into all-out war. The icon of the bladed wyrm-form is carried by all the dynasty's members, whether they be the Brood Brothers of New Gidlam's Astra Militarum regiments, or the hiver gangs themselves. So militarised is the cult that the icons themselves are weaponised, appearing in stylised form as knuckle dusters, throwing stars or daggers. They are often used to slay those who stand in the cult's way, an act rich in symbolism originally started by the cult's Magus. Perhaps unwittingly inspired by the coming of Hive Fleet Leviathan, the brotherhood of the Hivecult wear regalia of bone-white and purple. There are those in the Imperium aware of the cult's infection of New Gidlam and their infiltration of the Astra Militarum defenders. However, each hive city's populace numbers in the billions, and the cult is well versed in the arts of secrecy, revealing its true numbers only when sure of victory.Innerwyrm - The Innerwyrm Cult infests the abattoir world of Fleishgate. A lynchpin planet that provides the meat of grox, grontock and bovian to the Mawdlin System, Fleishgate has long been taken over by a Genestealer Cult. They take their inspiration from the arm-length intestinal parasites they find within the guts of their livestock, just as their hidden cult grows strong within the fat-bodied mass of Humanity's ignorant herd. The use of the saw-spined wyrm-symbol, inspired in part by the meatslasher machines the Innerwyrm cultists use in their daily slaughter, is not confined to Fleishgate. Many cults have elements that use ripping circular saws, whether to grind rock, cut through steelwood roots or salvage the parts of industrial machines -- it is common for such broods to echo this sigil upon their own standards.Pauper Princes - The Pauper Princes have all but taken over the slum world of Chancer's Vale. Most of the populace lives in the squalid shanty towns that pepper the coasts, their skin badly desiccated by the constant salt-mining of minerals from its barren seas. Such is the deprivation and abject poverty of this Imperial world that many of its people turned to worship of the cult -- not because they were forced to by coercion or the Genestealer's Kiss, but because they are desperate for a way off-planet. The promises of Magus Marovitch Tenndarc saw swathes of the world's populace united in their devotions to the Star Saviour. Every Emperor's Day the Magus sermonised to rapturous crowds about the glories to come. Magus Tenndarc died saving the Star Saviour himself -- the cult's Patriarch -- by diving in front of a Ratling sniper's bullet. The Abhuman assassin was torn to pieces within the solar hour, Tenndarc attained the status of saint, and the cult's flock quadrupled in size. Gene-sects of the Pauper Princes also were active on the Sentinel World of Vigilus after the opening of the Great Rift where they became primary antagonists of Imperial forces during the War of Beasts.Rusted Claw - The worldwide Minecorps that toils beneath the Mining World of Newseam unearths hundreds of tons of precious metal from the planet's crust each day. The sickeningly rich upworlders forbid the downtrodden miners from keeping the metal they dig out from the seams, let alone spending it, but much is smuggled away nonetheless. Known as the Cult of the Rusted Claw, this embittered brotherhood believes that the all-consuming emptiness of the void devours all, even metal. They see the tarnish of every coin and the rust that eats away at every vehicle as divine entropy brought to their world by their Patriarch, and they welcome its spread. Only when the oppression of the upworlders is gnawed away completely will they be truly free. The hybrids of the cult believe that an eternally hungry beast called the metallophagic wyrm will devour not only the flesh of the unbeliever, but also his creations. Their symbol shows the cog of industry being consumed by the wyrm-form that represents the Patriarch's great hunger.Twisted Helix - Hailing from the macro-alchemical distilleries that provide the medicae-class Civilised World of Vejovium III with its exported medicines, the cult of the Twisted Helix has spread far and wide. The cult's broodkin skulk in enormous medifactoria that appear from the aristocracy's spires like the laboratory of some godly sage, all spiral glass pipelines and chimneys that belch strangely-coloured smoke. At a high cost in volunteers' lives, the magisters of the industrial cult have learned how to extract the germ-seed of the Genestealer and incorporate it into the curative syringe-phials that form a major part of Vejovium's medical exports. Though the imperfections of this bio-alchemical breakthrough have resulted in a great many aberrations and metamorphs, the process has seen the Twisted Helix swiftly spread its curse across the Vejovium System...and far beyond.Cult of the Four-Armed Emperor - The Cult of the Four-Armed Emperor was originally incepted by the Trysst Dynasty of the "Delverworld" of Ghosar Quintus and represented the first Genestealer Cult ever encountered and officially categorised by the Imperium in 680.M41. It spread its dire influence far and wide before coming under attack from the Deathwatch of the Adeptus Astartes. A dozen new infections have since grown in its image -- the Genestealers the original Tryssts sent to other planets under the guise of industrial shipments have sired new generations and variant cults in their turn.Cult of the Second Son - On the infamous Hive World of Necromunda, the spire-like edifice of Hive Secundus was known for being rich in spirit and enlightenment as well as material wealth, more so even than its peer structure, Hive Primus. Scholars sought to learn the mysteries of the Imperium from its extensive archives, and were so entranced by what they found they never left. But its outward appearance was a sham, for Hive Secundus was under the sway of a vast and frighteningly influential gene-sect. When this fact finally came to light, the lord general of Hive Primus ordered the bombing of the rival metropolis with high-yield rad munitions -- so thorough was this bombardment that the entire hive city, built far taller and thinner than its counterparts, toppled onto its side with an immense crash that caused seismic disruptions for hundreds of miles around. The entire area was declared quarantine extremis, and the denizens of Necromunda forbidden from even talking about it. Unfortunately for the hive lords, the bombing of the spire and its subsequent toppling did not prove enough to eradicate the cult that lurked at its heart. So hardy and determined were the cultists that hundreds of thousands of them survived, and ventured out once more through the extensive tunnel networks that tendrilled from their old haunts. The underhive gangs of Hive Primus, their interest piqued by the very forbiddal of raids upon the fallen metropolis, entered those same tunnels. The troglodytic creatures they found in there were mutated beyond all reason by the baleful emanations of the rad bombs -- and every bit as lethal as the Purestrain Genestealer from which they had been born.The Brotherhood - The Brotherhood was a Genestealer Cult linked to Hive Fleet Kraken that rose up on the Imperial Hive World of Ichar IV in the days just before the start of the Second Tyrannic War in 992.M41. Their rising was the precursor to the Kraken's arrival in Imperial space. The Brotherhood's rebellion was ultimately defeated by the intervention of Inquisitor Agmar of the Ordo Xenos and the Ultramarines Chapter under the command of their Chapter Master, Marneus Calgar. Later, as Hive Fleet Kraken swept through the same region of space, it would be discovered that some elements of the cult had survived and would aid the Tyranids during their own assault on the planet. Eventually, with the combined support of the Ultramarines, Ichar IV's Planetary Defence Forces and the Astra Militarum, the Inquisition successfully destroyed the invasion and cleansed the planet of all remaining Genestealers and Tyranid bioforms. One of the Astra Militarum units involved in the fighting on Ichar IV was the 13th Penal Legion, the so-called "Last Chancers." The bitter fighting resulted in terrible casualties for the Legion.