The crucible of imagination glares red hot with the fuel of inspiration, stoked by the fires of indignation and imagination. And into this vessel base materials are cast to join together and come out better at last. At least, this is the lofty ideal I aspire to, and that is more than can be said about people who came up with Tyranids. The less said about people who actually choose to play them the better. However, the space bugs can serve as an auxiliary source of inspiration in faction design, and as a good visual shorthand for imagination, as well as source of miniature proxies. After all, the fine folks who play good yet non-mainstream rulesets - Stargrunt II, Force on Force, Tomorrow's War, No End In Sight, Five Men In Normandy, etc - are used to buying generic miniatures and making them fit within their fluff. And why not enrich your setting with some alien flavor inspired by the writings of Ivan Sorensen?
Much like Stargrunt II, Gruntz 15mm, Hammer Slammers and a hundred other similar rulesets, Clash on the Fringe is all about keeping cottage industries of generic, 80's and 90's inspired sci-fi miniature manufacturers afloat.
"Blessed" Ivan runs the Nordic Weasel Games and produces FiveCore rulesets beloved by many a historical gaming grog. He has also done forrays into sci-fi; Clash on the Fringe is his platoon-level (30-ish dudes, maybe a vehicle or two) game set in the generic Fringe universe. The book (and the setting) comes with several factions inspired by other works and settings, and one of those is a group clearly inspired by Chaos. They are twisted and transformed humans and aliens in the service of some mysterious (not-developed) Dark Gods; one biit of flavor text mentions a character shooting a monstrous standard bearer. Generic and low on detail they may be, but these guys sparked my imagination a lot more than of the (dime a dozen) invasion of body-snatching body-horror worms.
But where do Tyranids come into play? For those blessedly not in the know, Tyranids are Warhammer 40K's space locusts. Extremely adaptive, biotech-only extragalactical aliens driven by a hive mind, but basically space locusts. Imagine the Zerg if they had no motivation or characters or fun, and you have the Tyranids. They also appear to have a fanbase utterly developed to crying about the latest rules release (to be fair, than can be said about every player of 40K). One other thing about the Tyranids is that this bland space-borne insect swarm has a strain dedicated to being fifth-column infiltrators. Genestealers (often seen tearing apart incompetent Terminators in Space Hulk games) are close combat monsters that also infect humans, who then produce hybrid offspring. 4th generation hybrids can easily pass for humans, while the earlier ones have forehead ridges and additional arms. These hybrids form genestealer cults who infiltrate a planet's society and eventually launch an insurection that leaves the world open for the 'nids to come in and eat everyone and everything (including the stealers). It's still unknown whether the Marker cult from Dead Space cribbed this idea and which of these two cults has a shittier background (even with my intense dislike of Tyranids, Dead Space's reveal of what stands behind the Markers is still a good contender for being worse).
Tyranids are what the God-Emperor finds scurrying about when He turns on the light in kitchen.
So why not make these cults into actual no-shit cults that are the vanguard of bizzare alien crusader fleets? Here's how it goes: the purposefully vague and obscure Dark Masters are really fucking alien. You can get Chaos gods to some extent (they are formed from mortal emotions) and the C'tan just want power and lifeforce (or maybe souls? Not even the fluff writers are sure). But these Dark Masters are non-Euclidean-geometry alien. The way people go crazy when they try to explain eldritch horrors in Cthulhu? Anyone trying to explain these gods would also sound insane. That's why they need a corrupting agent to bring sentient creatures about to the correct mode of thinking and get religious about their new masters. So the genestealers, who aren't actually stealing any genes (and they weren't doing that in 40K; they're more gene-givers), are the vanguard missionaries of their gods. They infiltrate worlds where they give humans (or other species) the mutation or whatever that is needed to hear and understand the call of their masters. The author should never really formulate what that is, because these are truths that not only don't make sense to anyone, they're also not expressable by words.
Anyways, genestealers (and their poorer jeanstealer brethren) infiltrate a world's power structures and work to compromise its defenses, eventually launching a coup or a rebellion. While it looks like just another colonial civil war (colonists have to keep themselves entertained somehow), its actually the preparatory sabotage work donw while some beacon-altar is broadcasting a signal to the fleets. The Dark Masters might actually be telling the genestealer patriarch that the time is ripe and a fleet is underway. In any case, a fan starts feeling that shit is about to violate its personal space. The horrified sci-fi militia in 80's sci-fi gear notices that some of the rebels have deformities that no amount of inbreeding can explain, but it's already to late. The sky is swarming with biological ships that must have hatched from the dreams of H.R. Geiger. These giant sacred cows/prophets/meaty space temples of the Dark Masters start disgorging horde upon horde of horrifically (yet uniformly) transformed faithful armed with the panoply of tools of conversion.
Old-school genestealers stole jeans and hairspray
For you see, while the Tyranids focus of being a force as interesting as dry paper towels and trying to eat everything forever (and not in a fun way like WHFB's ogres), the Hordes of The Dark Masters are coming to convert everyone. This is a truly universal religion and everyone is invited. Those Posoined (4+) weapons? Yeah, they're paralizing, choking and otherwise incapacitating. All those scything talons and other spiky bits are for maiming, not killing. And as long as the lay person survive, any damage done will be healed in the conversion pools. Sure, they can't get everyone and some possible converts (and believers) will die in the process, but it's all worth it for the voices in their heads. The Dark Masters speak and the whole universe will hear them.
So while Tyranid infested worlds start sprouting spines for no reason and digestion pools bubble up everywhere to process the planet, the twisted biological growth that follows the Hordes of the Dark Masters turn the world into a massive temple. The spines are pillars and obelisks venerating the gods, chitinous pulpits for the chosen faithful to stand on and try to articulate the will of the gods (it's still impossible to put it into words, but massive congregations are still enraptured by the attempt). The skies are roiling and red (but without faces in clouds, that's Chaos business), a giant spine juts out in the middle of the plains, and a massive multi-limbed prophet is shouting nonsensical dissonant sounds to the eagerly listening masses that carpet the ground. Bubbling pools are places where the unbelievers are taken to be changed into the faithful and be presented with new, blessed forms. Spores and clouds and growths make the planet more... holy. Stuff that you would see in Darkseed or Beksinski paintings is spreading everywhere, covering architecture, twisting the local biosphere into a new, sanctified imagine. Alien growths, neither plant nor animal, bear strange unnerving fruits to feed the masses, and eerie critters run in the shadows. A chain of these holy worlds marks the passage of the crusade.
Watch the Scorn trailer for inspiration, imagine everything being more scarlet than gray
And therein lies the tremendous possibilities of the faction. If the Warhammer writers wrote themselves into a corner and made Tyranids basically invincible, then the alien crusade might have strange twists and turns, and odd Piligrimages where victorious fleets turn back to go to the Source, where lightning-wracked nebulas thin out the herd and only the select few return with renewed vigor and enchanced physiques. Meanwhile, the newly conquered worlds are busy with the process of conversion. Destitute survivors are guarded by alien beasts as one by one they're fed into the pools to be changed. This ups the stakes for everyone else since the worlds still hold value after being conquered, and there's a time limit for saving as much of the population as possible from conversion. Better yet, the world might be reconquered, but it still has to be reclaimed. Do you try and make a life in this new hellscape, feeding on squirming food and clearing the pulsating veiny growth to build new buildings? How can you purge the taint? Will the hordes be back to reclaim a world shaped in their masters' image?
There are other things to work out, too. Well, not about the Dark Masters, since they have to be really mysterious: anything you can come up with will not be as cool as the sense of wonder and suspense. Never explain who they are, where they come from and their motivations. Their crazy following is what matters. And we can't talk about those guys without talking about their Tyranid inspired forms: how does the transformation take place? Do different species produce different forms, like Shhadowrun's HMHVV virus? Are, say, humans transformed into gants, and Space Marines into Warriors? Does everyone start out as a gant, and once they prove their worth, they get dunked again to rise up as a superior form? Is every gant a convert, or is it that only Alphas are former people, and the rest of the pack are stupid animals they lead (would explain the instinctive behaviour)? Who gets to be a genestealer? Do successful stealer patriarchs get transformed into tyrants? Do stealer hybrids who showed their worth in the fighting get bigger rewards? Is it similar to ork leadership, where size equals rank? Of course, you don't need to stick to Tyranid lines that close if you're not using it for 40K or 'nid miniatures and you have a lot more leevay with the transformations. And you don't nhave to use the 'nid names, either. If you can run Hordes of the Dark Masters with other minis, more power to you (also, please share links to the manufacturer). And if you want, you can dress up your monsters in clothing, tatters and bits - while the hordes are unlikely to feel the need to hide their divine shapes, who knows how it works in their minds. Hell, you can probably model gants with AKs and lasguns!
Finally, a cool way to use the new line of genestealer cult minis!
Of course, there are more things to be developed, like the unique naming conventions and ship forms. Do they have blind faces or anything the like? How do you make them freaky, instead of just floating space bugs? All this and more (except for the nature of the Dark Masters) is to be answered by the ardent modeler and gamer. Obviously, that hypothetical person is luckier than me and knows miniature gamers that are willing to play rulesets that aren't that well known, field custom factions and buy generic miniatures. Alas, poor me...