I never got the impression that the Dark Eldar could just "turn it back on" when it comes to psyker powers. My understanding of it is that not only do they do all that stuff to stunt them but also after 10000 years of selective breeding, cloning, and killing off their own powerful psykers that the Dark Eldar have genetically stunted their potential to the point of irrelevancy. Maybe the occasional Archon, but those guys could have been born only a few years after the fall and are thus not affected by the gene degredation. A sorcerous pact would change that, sure, but I really don't think its common or acurate. I don't think your average Kabalite Vatborn will ever be worth a shit as a psyker without some serious chaos dabbling, and I don't think refusing additional stunting proceedutes is sufficient as they've already nerfed themselves.
Slaanesh has an almost all-consuming desire for Eldar souls. The psychically sensitive nature of the Craftworld/Exodite Eldar means they would probably be driven irreversibly mad by the emotional tides bombarding their minds and souls if they were to stay around Chaos for long enough. Chaos Eldar would be short lived, but extremely powerful. Almost like a further extreme of Chaos Psykers in the case of Craftworlders and Exodites. Dark Kin, I'm not sure of, they seem to be a lot more psychically sensitive than the average Human, so there's still potential for them to develop Psyker-like abilities while under the influence of true Immaterial corruption. As for all this "Khorne wouldn't want them," business. Khorne would have almost no problem with making a Psyker his champion if the Psyker refused to use his/her gifts under any circumstances, even more so if those gifts were never nurtured to begin with.
It also makes me wonder if some forsaken exodite world out there has given into their fate of being extensions and damned to Slaanesh -believing the only way to prevent themselves from being forever consumed by Her, is to gain enough favor to reach Demonhood - as being by Her side forever is a better fate than surely being devoured by She who Thirsts.
I think that the verb was wrong to begin with. Incubi are the only known dark eldar to worship him. Acknowledging and possibly respecting is not the same as worshiping. This isn't the same Khaine as in Warhammer Fantasy.
Nor is it the same people and not measured by the same standards of worship. I am not applying the word worship in the same sense as if they are a theistic people because as a whole they are not. You are mistaking the context of the word and its use. Dark Eldar worship is not the bowing and scraping that humans in 40k ascribe to it. Ironically, it is something more akin to how a polytheistic people would interact with their various deities: acknowledging their divinity but not directly worshiping all of the deities; it is in this sense that I said that the Dark Eldar worship Khaine. I do agree that the majority of his direct worship comes from the Incubi.
Part of the reason their souls are being slowly eaten is because of the presence their souls have in the warp (a.k.a. psychic resonance). It is through this information we can make the educated decision that they are all still latent psykers because as we know: the more powerful the psyker the more presence in the Warp he/she has. Your average Kabalite Vatborn won't live long enough to be able to be "worth a shit" as a psyker so of course they'd never develop into one. Not to mention the total decimation that would follow if the eye of Vect should fall upon the would-be sorcerer. That brings to mind that the average Dark Eldar would not have the resources to begin to "safely" begin to dabble in their latent psychic powers; because in every novel and codex I've read it's only been the powerful who have had the resources needed to hide such goings on. From the OP the context given was one of a "demonic Sorcerer Eldar".
Citation needed. (Either way, non-psykers of various races have plenty presence in the warp, exempting some races like Tau.) What? You don't need to be a psyker to have a presence strong enough to be noticed in the warp and acted upon. Humans that draw the attention of the chaos gods are so influenced all the time. Eldar definitely "draw the attention" of Slaanesh enough to qualify. The Eldar (including the Dark Eldar) have a connection to Slaanesh because they created her, she contains a lot of what it means to be Eldar. Especially after eating almost every other Eldar and Eldar God, all of their essence inside of her and part of her. No further reason is required. As no further reasoning is required, we cannot draw conclusions from this fact in the way you have tried to do. Your claim is based upon an unconfirmed assertion you have yourself made. Personally, I think that Dark Eldar have selected against their psychic affinity for centuries, slowly diminishing it. We know their physical prowess is superior to the craftworld eldar because of exactly such an effect, so enough time has clearly passed for such changes to become apparent. As the infertility of the Eldar is also linked to the increased psychic potential they received, this may explain why they are apparently not suffering from population deficiency, even after factoring in cloning. Just my own fancy though (of the same level of credence as yours), no claim to absolute truth. What's more, it is noted that the Dark Eldar were changed by the Fall, they were twisted in some way. It is entirely possible that this blemish is the only thing Slaanesh needs to find them. As an aside, I wonder if the Path of Damnation simply leads to becoming more like the Dark Eldar, not necessarily to chaos worship.
In the Path of the Dark Eldar omnibus a couple of times different characters went to Shaa-Dom and the narrator explained that their psychic awareness was kindled further and the tug of Slaanesh was made stronger. You ignored what I said after your cut "because as we know: the more powerful the psyker the more presence in the Warp he/she has." which puts my quote in an entirely different context. The fact of the matter is: all Eldar have a stronger presence in the Warp than most races do and this is because all Eldar are latent psykers. Dark Eldar, through millennia of disuse have atrophied their abilities but that does not mean they do not exist. Pair bonded individuals for instance can use a private form of telepathy (one of the very few psyker powers allowed in Commorragh) but are so rare because of the level of trust that it takes for the Dark Kin involved and not because of the lack of raw talent needed. As I said, them having bright souls in the Warp is only "part of the reason". Another is the connection their particular race has to Slaanesh. This, however, does not exist in a vacuum as seen when the other Gods awoke around M2. Citation needed. The only things I've read about their fertility problems are because of slow rates of maturity (about a century to become an adult), slow gestation rates, slow cycles of fertility in Eldar females, and in the case of Craftworld Eldar their Paths are so stringent that children are a rare consideration. Slaanesh can find any Eldar due to their connection to the Warp even the Exodites who left long before the Fall.
I ignored it because it wasn't relevant. Psykers would have a larger presence and be easier for Slaanesh to get at, yup. Doesn't mean that, ergo, they are psykers. Humans have enough of a presence, so if Dark Eldar had no latent psychic abilities they would still get eaten. That means that, no, the fact that they get eaten does not prove that they are latent psykers, as one is not a requirement for the other. Just to clear it up: I don't disagree that they probably are latent psykers. I take issue with the odd jumps of logic you use to arrive at that. I'm not beneath playing devil's advocate when someone I do agree with makes a post that contains element that, even with our shared viewpoints, don't make much sense. Pair bonding is a much better example of how they clearly are latent psykers. Stick to that rather than claiming that it "is through this information that..." when that doesn't follow at all. "Before his comatose imprisonment in Slaanesh's stomach, Asuryan performed one of his greatest acts: binding his psychic might to the Eldar, preventing Slaanesh from absorbing all of his power. The psychic power bound into them by Asuryan brought both boon and bane to the Eldar. Though the Eldar's lifespan and already potent mastery over psychic energies increased following Asuryan's gift, it decreased their fertility, leading the race to begin a slow decline." http://warhammer40k.wikia.com/wiki/Asuryan You can track the original sources down from there Slaanesh can find any Eldar, but the only Eldar that get slowly devoured are the Dark Eldar. Craftworld and Exodite Eldar are forfeit once they die, if they don't save themselves with soulstones and the like. Only the Dark Eldar get devoured piece by piece while still alive. That is the fundamental difference in their souls.[/QUOTE]
It is entirely relevant if you're going to quote me, you should quote me in context. Beings closely tied to the Warp (psykers, daemons, etc) have a larger presence in it. I'll quote from the 2nd Ed Eldar Codex: "If an Eldar's spirit is not captured ... it is absorbed into ... the warp... To a human such a fate means nothing, for virtually no human mind is strong enough to retain a sense of consciousness after death - - the psychic energy of the human mind being paltry compared to that of an Eldar. Yet to an Eldar to enter the Realm of Chaos as a conscious spirit represents the ultimate horror. In the warp there is nowhere an Eldar spirit can hide from the daemons." Eldar souls, regardless of Exodite, Craftworld, Dark, or otherwise have strong enough spirits that they can maintain a consciousness within the Warp. Odd jumps of logic? Applying logic to a fantasy realm where magic is ruled by a tainted realm of impossibility formed by extreme emotions requires it. There are certain "rules" that are followed even by Chaos and having a larger presence in the Warp means you have a higher potential to manipulate it is one of them. Hmm, that's interesting. I just looked through all three of those books and it made no reference to that happening. 3rd Edition Codex has almost zero lore in it, while the 2nd Edition Codex has loads more lore about the Fall in it there was very little reference to Asuryan in it; more importantly there was no mention of him decreasing their fertility. I'll reread it at a better opportunity. That's because the others anchor their souls to spirit stones. Dark Eldar on the other hand would never let their soul be tied to an item so easily destroyed or stolen by their kin.