|This article or section involves Matthew Ward, Spiritual Liege, who is universally-reviled on /tg/. Because this article or section covers Ward's copious amounts of derp and rage, fans of the 40K series are advised that if they proceed onward, they will see fluff and crunch violation of a level rarely seen.|
The Nemesis Dreadknight is a Grey Knight suit of armor that allows its wearer to go toe-to-toe with a Greater Daemon of Chaos on his own. Yes, the regular plot armor does have its limits, and even an above-strength chapter can't always send the hundreds of Battle Brothers that would normally be required to contain such a powerful daemon.
Wearers are recognized as being the most formidable of Knights; unfortunately for them, this means that they get stuck with the really dangerous missions.
Per fluff updates, we learned Magnus the Red can swat these things aside like god damn flies. The bad old days of the incorruptible daemon-slaughtering fuckmachine seem gone for good.
Design (And Flaws)
The Dreadknight suit isn't retarded in and of itself-- a Dreadnought-sized suit of armor that doesn't require the operator to be near-dead is a reasonable thing for a chapter to have, hence why most chapters have Terminator and Centurion armor. This is especially true for the Grey Knights, as they regularly take on massively powerful daemons with relatively few Knights, and while they are proportionally swimming in Dreadnoughts, they could always use that firepower in a usable form any Grey Knight could jump in. It does lead to some shoe-on-head grade rules interactions, like how your techmarine can repair your dreadnought but not your dreadknight - although that one is surprisingly justified (see below - everyone just shoots the driver).
The problem is that that it looks really silly. As in, "the pilot looks like he's in a baby carrier" silly, and from a distance it looks like a hideous mishmash of mechanical bits and pieces to boot. Even a Penitent Engine, which arguably has the same sort of shape, has the contrast of some hapless victim chained against an enormous metal monstrosity surrounding it, while armor on top of armor in the Dreadknight's case gives it no dominant contours or lines in the same way that, say, a Dreadnought or Battlesuit does.
Combine this with the crunch giving the Dreadknight the saves of Terminator armor and the look of the pilot already wearing Termie armor, meaning by all accounts whenever he's getting hit, everyone with half a brain on the enemy's side is shooting him out of the middle, and you get a look so incompetently-designed that even "because grimdark" can't explain why it turned out that way. It really does look like the designer was watching Dexter's Laboratory/Matrix and thought his backpack robot suit was great Imperium material, or they saw Aliens at the time and thought that the Grey Knights needed power loaders.
Add the Grey Knights' checkered reputation with the community up until 6th Ed and you get what could be the undisputed champ of units kneecapped by fluff. Awesome as a Space Marine wearing a fuckoff-huge suit of armor to go beat up really big things could be, if it's not another toy for the shiny special snowflake chapter, it's also one that doesn't even have the courtesy to look sensibly designed. Cue mockery.
Since a lot of the Dreadknight's problems are fluff and aesthetics-related, it's very easy to make a better dreadknight with a little lateral thinking: just replace its baby carrier torso with something a bit more logical. Feel free to model one by attaching its limbs to the chassis of a dreadnought to give it a torso that makes sense. A quick Google search will give you plenty of reference models to work off of, and as long as it plays like a dreadknight, nobody will care all that much. Exposed-head chassis seem to be pretty popular for this, so you can't have everything, but screw those models. It's your dreadknight and nobody can tell you how to build it as long as it's not sillier than the stock model.
Really, when you get right down to it, if you think about the dreadknight bitz as two arms and two legs with where the baby carrier would go as a blank canvas, the possibilities are infinite. Make a beefed-up dentinel. Create a penitent engine on steroids. Have orks loot it and turn it into a kustom mega dread. If you have money to toss away, buy a knight castigator and work from there. Noughtknight conversions are just the beginning.
The bad rep masks what's not a bad unit, all things considered. It's expensive, but then again everything in the Grey Knights' arsenal is, and it gets customization options and status as a Monstrous Creature with the current rules. While it and the Riptide are the only MC that don't get Fearless, with S10 and Terminator-level durability it's not a bad choice, all things considered, and by virtue of being that combination of tough, strong, and ugly, you can guarantee the guy on the other end of the table will immediately try to kill it and ignore everything else in your army. Give it close combat upgrades, wade into battle, and watch as your Termie on stilts puts a hammer up the ass of high-point units out on their own, as long as you don't get hit with tank shock or some similar effect.
All in all, it requires more attention than other MCs, and though you can put guns on it, it won't be helping the Knights get any shootier at range, but it's at least got its uses, especially in close range combat. It also can bring along a personal teleporter for 1/4 the cost of a stock DK, which is an almost must-have with the points reduction in 7th Codex. If you must take one along, though, rest assured you can do things with it and royally fuck up some special snowflake's day, especially if it's one hiding behind Warp or psyker effects.
They are also good at getting objectives: they're pretty fast, they're very killy, they're tough and they're on the cheap side (225pts fully kitted out) for what they do. Anyway, why should 'nids and daemons be the only ones to use giant psyker MCs to grab objectives? Anyway, we have the best one for taking them, if not holding them. Now, if only we could get ObSec like tervigons...