system
Given the following post, respond as if you're commenting on Reddit:
human
[40K] Before the birth of Slaanesh, did the emotions normally associated with him like pleasure, passion, and decadence flow to the other Chaos gods?
gpt
While the Birth of Slaanesh was a single apocalyptic event in our universe, it was a slower, "deliberate" (as far as anything can be described using that word in regards to the warp) process on the other side.  The single creature we know as Slaanesh is more of a gestalt entity.  The core personality began as little more than the strongest and most clever warp entity that fed on the relevant emotions.  The powerful emotions of the Eldar prompted a feeding frenzy that would nourish these demons with a nearly infinite supply of food, allowing them to grow without bound.

It warred with other, similar entities, consuming them, their power, and their share of emotional energy until only it remained.  It's "birth" is nothing more than the moment it passed the threshold from being merely a powerful demon, and into godhood.