Full of cool artwork we have a good look into the Slaanesh here. One of those mysterious Gods of Chaos, Slaanesh has been one of rumor and conjecture since the inception of the Age of Sigmar. While I am looking more towards 40k, there is quite a bit of good information here.
via the Warhammer Community
https://www.warhammer-community.com/2019/04/18/apr-18-slaanesh-in-the-mortal-realmsgw-homepage-post-3/
Battletome: Hedonites of Slaanesh is on its way, kicking off a long-awaited new age for the servants of the Dark Prince. Today, we’re looking at just how this youngest of the Chaos Gods works, how he came to the Mortal Realms, and just what he – and his followers – are up to right now…
What is Slaanesh?
Slaanesh is the Chaos God of obsession and excess. All the Chaos Gods draw their strength from the emotional animus of mortals, and Slaanesh is no exception. However, the Dark Prince is unique among his brethren in that he does not represent a specific, crystallised, concept like rage, ambition or despair, but instead draws strength from the intensity of any given emotion – any form of excess feeds Slaanesh.
This makes Slaanesh terrifyingly powerful, to the point where he is secretly feared by his brother gods. Each god risks being consumed by Slaanesh, as each is an embodiment of the all-consuming ideals, mindsets and obsessions that sustain the Dark Prince.
How Slaanesh came to the Mortal Realms
After feasting on aelfkind during the End Times of the world-that-was, Slaanesh, for a time at least, surpassed his brethren in sheer power and influence. Despite being near-stupefied from his feast of souls, the Dark Prince was stirred from his digestive lethargy by the discovery of the Mortal Realms by Chaos. This was not just one world, but eight – a prize the Dark Prince sought to claim for himself.
The Age of Myth
Slaanesh’s war on the Mortal Realms was subtle at first, snaring mortals with distant echoes of sensation. As civilisations grew, so too did their tastes for vice and excess, with cliques and cults of self-advancement and pleasure allowing ingress for the creeping influence of Slaanesh.
Slaanesh’s greed was ultimately the cause of his imprisonment, leading him to be trapped between the Realms of Light and Shadow as he sought to devour the aelven gods. Slaanesh has a particular taste for the souls of aelves, who are by nature passionate, obsessive and focused creatures with highly attuned emotions, so the promise of consuming an aelven deity – let alone four! – was too much to resist. This gambit, perpetrated by Teclis, Tyrion, Malerion and Morathi, saw Slaanesh bound in vast magical chains and subjected to torturous pain as his captors drew the aelvensouls he had once consumed from his corpus.
The Age of Chaos
The capture of Slaanesh greatly reduced his influence in the Mortal Realms but did not stop it. From the Realm of Chaos, the greatest Daemonic servants of Slaanesh continue the work of the Dark Prince. Many empires fell to excess during the Age of Chaos, ultimately destroyed by Slaaneshi daemons that tempted mortals and spread corruption. At the Battle of the Burning Skies – the apocalyptic conflict in which Sigmar’s hammer, Ghal Maraz was lost – the Keeper of Secrets known as Luxcious declared herself to be the Ur-Slaanesh and a replacement for the Dark Prince.
The Age of Sigmar
The persisting influence of Slaanesh was felt particularly keenly during the opening battles of the Realmgate Wars – Sigmar’s campaign of liberation. The Chaos Lord Lascilion, in his arrogance, sought to slay Neferata, Mortarch of Blood, but was stopped by the timely arrival of the Stormcast Eternals.
Meanwhile, the Daemon Prince Synlesha Paleblood used the speed of his host to great effect against rampaging tribes of Orruk before being slain by a well-placed headbutt from the Megaboss Dakkbad.
Slaanesh Today
Over the long years since Slaanesh’s imprisonment, his followers have split into three main camps. Some, known as the Godseekers, obsessively hunt for Slaanesh across the Mortal Realms. Some hosts are known as Pretenders, led by particularly influential individuals who seek to usurp their missing god’s position. Others, known as Invaders, seek only to please their basest desires, reaving and killing across the realms heedless of Slaanesh’s disappearance.
Will Slaanesh ever escape? Will his servants succeed in conquering the aelves? We’ll have to wait and see to find out…