Lord of Excess is right up there with Fulgrim as “the” Slaanesh novel, kinda like how Lords of Silence is the definitive Nurgle novel.
I like that the EC in this are “charisma marines” if any legion can solve things without firing a shot it should be these guys. It’s got some time skips so far and the plot feels like it should’ve been a trilogy but Xantine is joining Decimus, Marduk, Vorx and Honsou as the “book only” Chaos Lords who are far more impressive than their tabletop counterparts who have models.
I hate the Fabius trilogy btw, it watered him down so much and took the badass monster maker who was one of the first corrupted marines (predating the birth of Erebus or the discovery of Chaos) and made him into an egalitarian, mouthpiece for what felt like author criticism of the setting. That shit sucked, the ending fast-tracking him seemingly back to Chaos (compare this man to how he is in Fulgrim and Angel Exterminatus, then try to tell me he’s the same guy) was bull. Also a human woman taking over an EC warband was straight-up bull, we know what these marines do to humans, no way they would listen to a mortal woman.