Alright everyone, we're almost done.
We're gonna cover the Dark Eldsr first, so grab your lotion, your hand sanitizer, and a brick of space cocaine because we're diving head first into the horrific slave pits of Commorragh.
DARK ELDAR
So the Dark Eldar are essentially the closest thing to a continuation of the Empire. In that their culture is pretty much unchanged from what the Empire was like before the Fall with one difference.
The pre-Fall Eldar did what they did for the hell of it.
The Dark Eldar do what they do because they NEED to. And for the hell of it.
The DE put together that due to just being close to the Warp, Slaanesh was still ever so slightly draining away their souls and would inevitably drain them of life. But, being inventive little knife eared pricks, they found a solution.
Be in close proximity to another sapient being suffering unimaginable amounts of pain.
This is where you get the DE leaving the webway pretty consistently to raid undefended worlds to wreak havoc and bring back slaves to keep their whole society alive a while longer.
Course the Webway is falling apart around them so they might as well enjoy themselves.
Oh yeah, forgot about that.
So the secrets to maintaining and expanding the Webway was lost with the Fall, so when age takes its toll and a crack appears a daemon could slip through, the DE can't actually fix it and the best they can do is place a huge number of automated turrets and traps in front of it and hope that'll dissuade the hell monsters from coming through, which so far has actually worked so I guess they aren't entirely wrong in doing this.
Politically Commorragh is a pit of vipers. I don't need to go into detail here just imagine Game of Thrones but a thousand times more back stabby and poisony. Really only mention I'm gonna make is it is currently more or less run by a guy named Asdrubael Vect who is possibly the oldest Eldar in existence since he was alive for and witnessed the Fall and clawed his way up from the bottom of Eldar society up to where he is now at the top, leaving piles of bodies behind him.
So that's the Dark Eldar, a bunch of ravers and reavers high on life and every drug imaginable partying and torturing in a city that could be gone one day.
Of course the disgusting slaving sweat goblins of Commorragh aren't the only Eldar out there, so let's look at them, shall we?
CRAFTWORLD ELDAR
Difference between Craftworld Eldar and Dark Eldar are night and day.
Those Eldar who survived the Fall on the Craftworlds saw what happened when the Eldar let their emotions and desires control them instead of the other way around, and so they developed a very plain and zen lifestyle so that they may always maintain their self control and calm even in the most perilous of situations. Their society and it's professions are divided into a variety of different paths that all perform different tasks aboard the Craftworld, and an Eldar who chooses a path usually stays on that path until they have perfected whatever profession they have chosen.
Or if an Eldar doesn't want to choose a path they'll either exile themselves or be exiled from their home Craftworld and become a:
A.) Mercenary
B.) Pirate/Corsair
C.) Ranger
An Eldar walking the Path of the Oucast may eventually return to their Craftworld and pick a path that isn't being a murder hobo space elf. Or they'll stay a ranger or go to Commorragh to join in DAT PARTY LIFE.
It would likely not surprise you at all to learn this path is made up of either disgraced eldar or youthful eldar looking for adventure.
One of the most important paths the Eldar have is the Path of the Seer. One guess as to what this one is.
Since the Eldar don't have the population to fight like they did in the old days, they have to make effective use of their limited population and take great care to reduce casualties on their side. They do this by having their Farseers put them ten steps ahead of their opponents, or by not fighting at all and pitting their enemies against each other through misdirection.
Of course don't think just because the Eldar are careful with their lives that they are unwilling to die. They are. In fact the grand plan of the Craftworld Eldar involves them dying. All of them.
What is the plan? Well...
All Craftworld Eldar have a little thing called a soul stone on them. When an Eldar dies with this on them their soul will go into the stone rather than the Warp. Other Eldar will take this stone and transfer the soul into a BIG soul stone on the Craftworld called the Infinity Circuit, which is basically like a purgatory for the Eldar souls where they just kinda... exist. The Plan is that when enough souls have been gathered (literally ALL the Craftworld Eldar by their own estimates) the collective energy and will of these souls will make Ynnead, the god of death, to drop kick Slaanesh into oblivion.
So in summary the Eldar's plan to kill the first god they accidentally made is to make ANOTHER god to kill the first one.
Yes, I know, it's almost TOO brilliant.
At least this WAS the plan, until SOMEONE decided he had a better idea.
8TH EDITION(a.k.a. the most recent stuff in 40k)
BIG SPOILERS AHEAD
So one of the oldest and most famous and respected Eldar Farseers, Eldrad Ulthuan, gets this nuts idea that maybe, just maybe, the Eldar don't all have to die to summon Ynnead. This was scoffed at by most Craftworld leaders because it was their turn with the in universe idiot ball, so they refused to lend Eldrad aid in this endeavor.
Of course Eldrad is kinda the 'beg forgiveness rather than ask permission' type, so he goes ahead with this anyway. He figures all they actually need to make Ynnead is a enough psychic concentration from enough powerful Farseers and enough power, and boom, instant Death God. He got the first by gathering those Farseers loyal to him and also the bones of the most powerful Farseers from each Craftworld. Which he stole. Then he found this moon just on the edge of the 'safe zone' around the eye of terror, covered in these crystals just bursting with energy. Mind you, these crystals were essentially crystallized Eldar remains that had coated the moon when the eye opened and killed about ninety percent of the Eldar population, and you may have noticed this is starting to perhaps sound maybe just a little bit like necromancy. Which it should. Cause it kind of is.
But hey, if you wanna summon a Death God, you gotta do a little necromancy.
So they get to the moon, set up, and get the ritual underway. And Just As Planned, it works.
Then the filthy humans show up and start shooting everything, as is our nature.
This fucks the ritual so Eldrad and co. have to stop it halfway through and run like hell before they get some new holes in their chests. They escape, but then Eldrad has to face all the pissed off Craftworlds who found the IOUs he left in place of the Farseer bones, and they find him guilty of space elf HERESY and throw him in magic prison.
Thing is though, even though the ritual stopped halfway, Ynnead still got summoned. He just wasn't at a power level where he could take on Slaanesh, and since the ritual got fucked by the filthy humans, he was gonna have to power up the old fashioned way, through worship. But for that, he'd need and avatar and prophet to lead the Eldar. So he started looking and found the perfect candidate.
Smash cut to sweat goblin town (Commorragh) and an Eldar named Yvraine is fighting in a gladiator pit with one of the deadliest pirate queens in Commorragh, Lelith Hesperax. And she's not doing great.
Up to this point Yvraine has led a storied life, she was born on a Craftworld, became a dancer, developed a bloodlust and became a warrior, then learned she had talent for psychic shit and became a Farseer, then she said 'Fuck this structured bullshit' and left to become a pirate captain for a while before her crew mutinied and she left for Commorragh for dat party life.
And now she's getting her ass kicked with most of Commorragh watching. She gets really pissed when she realizes Lelith is playing with her and not taking the fight seriously, and goes into a berserker like rage and actually wounds Lelith, which throws off the pirate queen because that wasn't supposed to happen. Lelith retreats to on top of a pile of corpses, Yvraine pursues, loses her footing in charging up the pile, then loses her hand, then gets a sword through the chest.
Then Ynnead swoops in and gives Yvraine a vision/job interview that goes something like this: 'So I've looked over your resume and you're a PERFECT fit for the job. You start immediately and no, you don't have a say in this.'. So Ynnead pours some of his power into Yvraine and this fixes the missing hand and fixes the whole 'sword through the chest' thing. Of course this big burst of psychic shit radiates out and blows up an already weak point in the Webway around Commorragh, so a whole load of daemons storm in to join the party. Vect immediately orders anyone loyal to him in the arena to kill Yvraine. Again.
But in a shocking twist, Lelith sides with the woman she just stabbed, and orders everyone loyal to her to protect Yvraine. What was originally a free-for-all gladiator fight has now turned into a team deathmatch with the whole arena involved.
Never say Commorragh is boring.
Yvraine and co. were still outnumbered and fled the arena, but surprisingly the ship from her pirate days was in Commorragh and let them onboard, you know, despite the fact they'd mutinied against Yvraine. They then flee Commorragh with a portion of the crew who MUTINIED staying behind to hold off Vect's troops while the important characters escaped.
Yvraine returns to her home Craftworld, which has... mixed opinions about her return, and fractures into factions. Some following her, some staying there others saying 'fuck this shit I'm gonna be a pirate.' Then she goes through a WHOLE BUNCH of bullshit to make an alliance with the filthy humans because they've FINALLY realized maybe the two races who have the most to lose against the literal eldritch chaos gods should work together. Finally at the end of all of this, Yvraine declares herself/ is declared the Emmisary of Ynnead, and she seeks to unite ALL Eldar beneath the banner of the Aeldari (which can still be pronounced like Eldar just add a little 'e' sound at the end) with the goal of kicking Chaos's fucking teeth in. Specifically Slaanesh.
Alright. That took a LOT longer to write then I originally planned. I'm very sorry for the delay.
But there's just one more section to cover, it should be short. SHOULD. I won't tell what it's about, but...