So...before you go all nuts...
Soulcrushers of Slaanesh
Chaos is capricious by nature, and never falls into predictable patterns. Each of the four powers have their own daemons who are recognisable and "common", but each also have their daemonic followers who are less recognisable. These usually are followers who have been warped beyond their original form, either sporadically gifted by their dark master on a whim, or to serve a specific purpose. Some are bred, again through either wicked desire to create something new or to serve a greater purpose. Others are just rare beast who rarely venture from deep in the Chaos Wastes, or have started mortal and been granted daemonhood.
Although Tzeentch is the greatest practitioner of creating new denizens and playthings, the other gods have trifled too. Slaanesh is no exception.
Seekers of Slaanesh are a graceful beast that are often tamed by daemonettes and ridden as a steed. Seekers ave, however, a much larger cousin. They oft go by other names; pleasureseekers, serpentines or soulcrushers, to name a few. These destriers are much hardier and larger, standing twice the size of a daemonette just on it's belly. Having the head of a seeker, and the body of a serpent, a favoured beast of Slaanesh, and the features of a human, they are truly children of chaos. No one knows their origin, but thankfully they are a rare sight indeed.
Daemonettes much first master their seeker steeds before they may attempt the pilgrimage to tame a serpentine. The serpentine has a foul temper, and to seduce it to ones will is truly a feat slaanesh would value in it's follower. Once tamed, the master will affix perfectly fashioned armour on their steeds head and shoulders, and adorn themselves in armour, almost in mocking of the knightly orders of the empire. The riders will also take great weapons, forged with fine blades and hooks.
In battle, the soulcrushers ride as a unit, their massive steeds slithering at incomprehensible speeds into the lines of their enemies. Between the lashing tail of their beast, and the finely honed weapons and artful approach to dispatching an enemy, the unit can provide a hammer blow rarely seen in an army who prides themselves on finesse.
So, there, I explained it. Stop accusing me of being cheesy!
The real story behind this is that I got the steed of slaanesh that the old chaos champion came with for a herald. Making it, I thought "Yunno, a unit of these would look cool!" So I bought another. I decided, since they needed monster bases, I'd use them as Bloodcrushers. Absolutely no cheesy malice was intended!
So here are the painting in progress pictures. Please, excuse the paint jobs, they're still in process of being made look right. The riders are just seeker riders given a bit of knife-and-glue love.
Here's the two I have so far ranked together.
Ah, Kiki, my rank and file. She used to be a japanese school girl, until a Kipper of secrets came to her with an oversized tentacle and...I'll leave the rest of that story for another time. She has pigtails. Yeah, I know, pretty cute! It's an army of hair fashion faux pas. She's got a hellion blade from 40k, I chopped her shoulders off and plopped some hellion shoulder pads on. I've given her steed a club tail, because their tails are a bit wimpy and I wanted some variation (and justify their huge strength).
My "bloodreaper", but I'll probably just use her as a normal grunt too. It's a standard arm with a corsair sword on the tip. This steed has a claw tail, for added clawpla finishing moves.
I've bought another steed, who will be a banner bearer taking the Banner of Endless Lust (war). It helps negate the pain us mono lists have trying to take multiples of our magic banners (laaame).