She Who Thirsts. Who is she? The tabletop wargaming/ roleplay gaming company Games Workshop invented this character and warhammer40k.wikia.com/wiki/Slaanesh explains Slaanesh thusly :

" Slaanesh, also known as the Dark Prince, the Prince of Pleasure, the Lord of Excess, the Perfect Prince, and even the Prince of Chaos in the Imperium of Man, the Chaos God of Pleasure, Passion, and Decadence. Lust, pride and self-indulgence are the hallmarks of all who follow him. He is the youngest of the Chaos Gods, having come to full sentience within the Immaterium only during the 30th Millennium. While generally referred to as a "he" by humans and as a female by the Eldar, Slaanesh is actually neither gender, combining characteristics of both and perfecting them. Slaanesh typically appears in an androgynous form in which it is a woman on the right side and a man on the left with two sets of devilish horns growing from its head. Slaanesh can assume any form; male, female, hermaphrodite or no gender at all, but it prefers male bodies. Its sacred number is six and the colours associated with Slaanesh are purple, pink and black. The name Slaanesh is a corruption of the Eldar term Slaaneth (Slaa meaning "ecstasy" or "pleasure" and Neth meaning "lord" or "prince" in the Eldar Lexicon; hence, the Prince of Pleasure), though ironically, the Eldar refer to this foul entity only as "She Who Thirsts."

Slaanesh is the Lord of Pleasure, the Dark God dedicated to the pursuit of earthly gratification and the overthrow of all decent behaviour, as well as hedonism and pleasure for its own sake. He is the God of Obsession, the Master of Excess in All Things, from gluttony to lust to megalomania. Wherever mortals are ruled by their own unquenchable desires, the Dark Prince of Chaos is there in the shadows, whispering, tempting, and feasting on a banquet of souls. But this is true in all things, not just carnal pleasures. Those who desire to indulge in the finest culinary delights, the most beautiful artworks, even the most sensual clothing, could all be amongst Slaanesh’s disciples. Just as importantly, Slaanesh is also the god of perfection. The singer striving for the most beautiful song or the warrior who seeks the perfect fighting techniques, both could be devotees of Slaanesh. "

In 2014 however I experimented with the egregore concept and performed some rituals to Slaanesh. They succeeded quite well! Something is answering to the name Slaanesh out there. Is roleplaying truly satanic after all. I would like to invite you to experiment and utilize this newborn god ov the abyss. Hail Slaanesh!