That means it is depraved (including sexual and traumatizing content) beyond comedic absurdity. The Dark Eldar are easily the most depraved race in the universe that coined the term, "grimdark". They are a bunch of space elf pirates who psychically feed off of the EXTREME pleasure and pain of other sentient beings. That means exactly what you think it does and they turn the dial up so high it just gets torn off. They are truly beyond comically evil. Their baseline is "slave blood orgy". Their mad scientist/dark witches drink virgin's blood and children's tears as they turn still living people into breathing, thinking furniture...and I don't shy away from any of it.

Is there any point in even trying to post it here?

I never thought anyone would describe anything in the Warhammer universe as "Comedy." lol. Anyway, I'm not sure if you are just low key bragging that you are much edgier than the average RR reader/writer since you can stomach the Dark Eldar more than others, or you are actually asking a question. 

As always, the answer to your question is, "It depends."

There are no issues if you simply describe the Eladrith Ynneas, as you did in your post, to inform your readers about who they are and what they are capable of. But if your story is about the point of view of the virgins and children as they experience the blood orgy and torture in descriptive details, then No. 

Again, there are other sites for that. 

On a side note, there is a noticeable lack of Warhammer fanfiction stories here in RR. So yeah, additional warhammer stories are welcome here, provided it is not a BDSM fetish story.

I believe there's a hard cap on sexual content featuring minors. So that's not something you want to actually describe as it happens. 

My favorite thing about 40k is the Harlequins. To me the brilliance of the setting shines as a black comedy. That’s applied equally as much to the Dark Eldar. They’re beyond comically evil and I want to depict that absurdist evil as basically a setup for my Harlequins to smash the punchline on. There’s just something beautiful about how laughing at edgie Sigma boys robs them of their power.

I’m writing a full tilt Dark Eldar 10ish chapter story for a setup to another story/karmic comeuppance. Tipping my hand, I’m showing every lurid and depraved detail of these monsters so that when I have them get their asses handed to them by a bunch of clown girls inspired by the sailor scouts it’s that much funnier 

Harlequin_of_Hope Wrote: I’m showing every lurid and depraved detail of these monsters so that when I have them get their asses handed to them by a bunch of clown girls inspired by the sailor scouts it’s that much funnier

I am afraid that according to the RR guidelines your story might be a bit too much for the platform. You are allowed to have a certain amount of smut and violence per book and with your story being "10ish" chapters, you are definitely going to exceed the allowed amount. 

Bear in mind that it's very hard to write a comedy that 100% of readers will recognize as such; with black comedy in particular, there's a risk that they'll think you're being serious, or worse yet think that it's unintentionally over-the-top funny.  Or else they might think you're being serious with all this torture-is-fun business and are the next mass shooter.  But you probably realize all this already.