Edgy

As far as I can make out "edgy" occurs when middlebrow, middle-aged profiteers are looking to suck the energy--not to mention the spending money--out of the "youth culture." So they come up with this fake concept of "seeming to be dangerous when every move they make is the result of market research and a corporate master plan".
- Daria, Episode [3.05] The Lost Girls.

Edginess refers to people trying too hard (and sometimes too aggressively) to make things more tragic, grimdark, controversial or cool. This often takes the form of senselessly driving a vague argument or scenario to its darkest possible outcome, all the while openly expressing their disdain at rationalizing villains or finding a middle ground in discourses. Like most internet terminology, it has been beaten to death, resurrected hastily, and then beaten some more. Has no relation to Hunter: The Reckoning.

Another far less negative use of the term is to describe something on the 'edge' of what's acceptable, pushing established boundaries of convention. For example, one could argue that Batman: The Animated Series was edgy for making an animated series which defied expectations of how true to its base concept and generally well-written a show designed to sell toys could be. A more direct example of this would be Ren and Stimpy (which was crude and vulgar) or Invader Zim (which could get get dark in subject matter, and used a fair bit of black humor); in both cases, a decent bit of the comedy was of the "I can't believe that they'd did THAT on a kid's cartoon show!" variety. A milder version of this was Sonic the Hedgehog (in contrast to Mario). For the 1990s and early 2000s Edgy was a favored term of cynical marketing types which drew the attention of the world's sarcastic snarkers, many of which came to congregate on sites such as 4chan.

An "edgelord" is someone who essentially is guilty of serial attempts to be edgy, like that guy at your tabletop role playing group who always, without fail, makes brooding loners with a troubled past (shit, they might also wear sunglasses at night) without the nuance or the skill to pull it off, and thus just constantly makes themselves look silly. "Art" done by edgelords contain characters who are as dark, brooding and as painfully unhappy as possible, conflicts have zero compromise, and any conflict of interest will have the worst possible outcome. An edgelord in writing will go out of their way to make the story extra depressing, and subject multiple aspects of it to an increased shock factor when it's clearly illogical to do so. Needless to say, it can drive a perfect idea to make an entertaining story into the shitter, grating the nerves of even the most jaded audience.

This is not to say that said dark elements like murder, slavery, rape and bodily harm are literally bad in of themselves, but rather that their sloppy execution with no regard to their depth is. As shown above, even the most "edgelord" of concepts can be salvaged and even made bearable with proper handling, especially going by the latter definition - but if you do it enough, the boundaries shift and what was edgy becomes the new norm, and there is always the risk of falling over the edge. This is why the old definition has fallen increasingly out of favor as time has gone on - people began seeing the dross sold under the title of "edgy", and the idea of what it meant thus moved away from the positive coronations marketing execs desired to the qualities described above. Plus, this is the internet, and people would rather a word just be an insult or a compliment to reduce confusion.

The Anatomy of Edginess

Edginess is in some ways like a cargo cult. During WWII in the Pacific, the US military set up bases on remote, but inhabited islands, bringing with them a lot of stuff like planes and cars and so forth that was quite amazing to the stone age natives, to whom the world had been a few dozen square kilometers of land surrounded by ocean, with hazy stories of other such islands. When the military left, some of the natives took to making coconut and wooden radios and flight towers based of some hazy recollection of the military variants, unaware that making the shape does not get you the actual thing.

Likewise, someone of (at best) mediocre creative abilities sees some fiction that makes good use of melodrama, gritty settings, dark humor and such, made by people who know what the hell they're doing and figures "I can do that!", leading to said person haphazardly applying those elements incorrectly. The results of such efforts are either tiresome, unintentionally funny or just painful. The stereotypical teenager, especially one of a Gothic/emo persuasion, tends to embody this - all too eager for "adult" things (eg: violence, sex and so forth) in their limited perception of such, often born of denial. Individuals who pander to said demographic (or are otherwise just downright hacks) will favor this approach over any sense of complexity, subtlety, nuance and some actual understanding of the human condition.

Edgy and Grimdark

While edginess is frequently associated with invoking grimdark for the sake of it and nothing else, it's important to remember that this alone does not edgy make. As an example, WH40K's Imperium of Man has reasons to be fair and kind when capable: though it has plenty of genocide, xenocide (completely annihilating species even when they are gentle and kind) torture, forced labor (though outright commercialized slavery does not exist), witch hunts and militarism that would give Hitler a chubby beyond the grave, but said horrors have reasonable justifications: Aliens were buying and selling humans like pets and culling them by the billion, operating slaver outposts even in our solar system before the Emperor came into leading the humanity into a roaring rampage of revenge. And regarding souls and the universe after the Heresy, any deviation from faith in the Emperor will literally send a human to hell upon death, one's soul becoming daemon food (and/or sex toy) if found lacking in faith.

Any mistreated machinery will attract foul entities and corruption that will fuck you up seven ways till Monday and chew you out; any ill-coaxed Machine Spirit will jam and blow up in your face; and any laxity will make Chaos cults pop up by the billion in a week. Then there's the genocidal robots from another age, space elves that would murder a planet on the off chance that their Farseer would break a nail otherwise, the ambulatory (AND belligerent) fungi that plague the entire Galaxy in a series of wars, and extragalactic horrors that intend to eat everyone's face. TL;DR The Imperium acts like an asshole Hitler/Hirohito bastard child because the alternative is much, MUCH worse.

Now if you want a senselessly edgy story in the Warhammer 40000 universe, an example would be the now non-canon Khornate Knights.

Notable Edgelords

• Drizzt Clones
• Sonic fan "original" characters
• DeviantArt OCs
• Many OCs, really
• The Night Lords Legion