C'tan

The C'tan are ancient and powerful Star Gods given physical bodies by the ancient Necrontyr, they're supposedly the spirits of dead stars or something like that, they are about as powerful in the Materium as a very strong Greater Daemon is in the Warp, capable of 'nomming entire stars with ease. They dislike anything Warp-related because it is the one thing they can't directly control with their powers, and may have tampered with humanity to inject the Pariah gene and probably built the Cadian Pylons which created the Cadian gate by creating a bubble of normality that cuts into the Eye of Terror. Can not directly enter it either. In 4th edition they were responsible for massive amounts of just as planned.

The first encountered was The Nightbringer, who was found "sucking" the energies of the Necrontyr planet's sun, the same sun that gives off enough hard radiation to make proto-Necrontyr life short, nasty, short brutish, and short.

The Necrontyr formed a necrodermis body and coaxed the star-sucker to inhabit it. This was C'tan later named The Nightbringer. When the Nightbringer awoke in the new body, it noticed the Necrontyr for the first time and discovered they were like Chinese take-out: really yummy and spicy, more so than bland stars, but you could eat a few thousand and still feel hungry an hour later. It took a while and much slaughter before the Necrontyr could convince the Nightbringer that they were more useful in servitude, and there were other yummy lifeforces to be eaten out there.

Other C'tan gods were discovered feeding on stars, but the most significant of the early ones discovered was named The Deceiver. Weaker than the others, The Deceiver is better at leveraging other entities to do what it wants. After inhabiting a necrodermis body, it adapted to the material world quickly and became very popular with the Necrontyr by means of cunning and guile. It was The Deceiver that convinced the Necrontyr they could escape their short lifespans and succeed in their battles against Old Ones by inhabiting necrodermis bodies themselves. The Deceiver neglected to mention that these new Necrons would be insensate, dull-witted and easily manipulated by the C'tan.

During the Necrons's war against the Old Ones, the C'tan also fought amongst themselves, destroying the necrodermis bodies they used to have an effect on the material world. By the time the Old Ones were rendered extinct, only four C'tan still existed in the milky way galaxy: The Nightbringer, The Deceiver, The Dragon and The Outsider.

Known C'tan

The Nightbringer - Here to fuck your shit up. The first C'tan to inhabit realspace. Scared the crap out of a race/culture that was a threat to the race/culture that created all the other races in WH40K. Likes killing, killing and, well, killing. In short: batshit insane though in a different way than the Outsider. Ate most of the other C'tan along with the Outsider, though he was convinced into doing so by the Deceiver while the Outsider was convinced by Cegorach. Pretty much a giant, mechanical, space Grim Reaper that shoots lightning. He once battled the Eldar war God: Khaela Mensha Khaine and lost, where he was subsequently imprisoned for millenia. Freed by Uriel Ventris and the Ultramarine 4th company, in other words; the Ultramarines have fucked over the entire galaxy on a scale not seen since the Eldar sexed Slaanesh into existence, and because Slaanesh is made of fail and weaksauce the Ultrasmurfs probably fucked up more as unlike Slaanesh, The Nightbringer actually gets shit done in the most fearful manner imaginable and never does anything that doesn't result in a body count in the tens of millions at the least. The Necrons under his authority who can still think tend to be the silent kill everything that's living, type with all the subtlety of an Angry Marine, in fact they hate life that much that even bacteria and microbes must be purged from any active Tomb World they inhabit.

(broken up for ease of reading) Is also Khorne's bitch. That's right Necron Fanboys, Chaos > C'tan. Deal with it. Says the guy who has the two shittiest codexes in Games Workshop history and lost an entire army. Not to mention the fact that the closest thing to a leader among the armies of Chaos is Failbaddon, who may have only gotten his sword because of the Deceiver's plans, which would make Abaddon powerful enough to be immune to starscreaming, and thus ensure that no one who was actually competent would ever become warmaster. It is a matter of some debate as to whether he or the Outsider is the second most powerful of the C'tan. He cut off Slaanesh's left boob in a fight once, subsequently this resulted in every last one of Slaanesh's daemons having only 1 breast (by canon terms anyway, doesn't stop drawfags from ignoring this).

The Deceiver - Mass dickery on a galactic scale that only Tzeentch could rival. Got the bright idea of convincing the Necrontyr to turn themselves into the zombie-mummy-skeleton-robots known as Necrons. Rumored to have implanted the Pariah Gene into humans to help combat the forces of the Warp. Spends his days taking part in "Just as planned" contests with Tzneetch, The Empra and Cegorach the Laughing God, which noone really wins in the end as everything they do results in a paradox. The (Intelligent) Necrons under his command tend to be sneaky and manipulative bastards with many of the Necron Lords under his command occupying many important positions in the Imperium of man and are the type of Necrons most likely to stop and chat with you, second most common type. One of them infiltrated the inquisition itself and set himself up as Inquisitor Raleigh of the Ordos Xenos in Xenology as part of a plot to learn humanity's greatest weakness, which turned out to be knowledge since humans are insatiably curious fucks which isn't actually that far from the truth. May be the reason why Failbaddon got Drach'nyen, which as stated above would make topknot too powerful to be killed and replaced by his fellow chaos space marines and ensure that only Abaddon's massive incompetence would ever be nominally at the head of the traitor legions.

The Void Dragon - Can exert control over any machine. Able to communicate with little children, regarded as the one C'tan with the most power over the physical world when at full power. It was said that the Emperor battled the void dragon and successfully managed to put it to sleep under Mars, he didn't intend to kill the Dragon, as so humans would be able to gain mastery over machines, Just as planned. It is rumored that the Void Dragon is the Omnissiah or Machine God who's currently fervently worshiped by the Adeptus Mechanicus as he's supposedly the entity that makes the ramshackle excuse for technology the Imperium has to work properly. There's also an Eldar legend of their forge god Vaul failing to destroy The Dragon but managing to get it to hibernate in a place called "the Vaul Moon." Was once shot at by multiple blackstone fortresses simultaneously, mind you, two blackstone fortresses can make a psychic laser powerful enough to blow up a planet death star style; all this managed to do was make him sleepy. In short, powerful as FUCK. He himself is a huge technophile and is to Machines as the Nightbringer is to death. The (Intelligent) Necrons under his command are probably massive technophiles with a raging hard-on for machines....then again they're already machines so this is probably granted, but they're probably bigger technophiles than their fellows and emphasize their mechanicalness over their undeadness.

The Outsider - Ate at the same C'tan-cannibalism saladbar as The Nightbringer but did so due to the Dickery of Cegorach the Laughing god instead of the dickery of the Deceiver, but feels bad about it; blames Eldar gods for his bad eating habits. Decided to say "screw you guys, I'm taking my ball and leaving," and currently lives in a Dyson sphere outside the galaxy. A hive fleet of tyranids decided to go AROUND this place, not just ignore it like tyranids do with Necron tomb-worlds. Were the tyranids scared? Dunno, it's safer to lick a bandsaw than stop to ask a tyranid. Other beings prefer to blow their own brains out rather then look at the Outsider when he's in town. Grimdark. The (intelligent) Necrons under his command are probably batshit insane.

Gallery

If someone actually fields these miniatures on the table, you're getting screwed.

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  The Nightbringer

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  The Deceiver