When we speak of Chaos your character may even eat daisies and shit rainbow and it's still legit.When I was thinking about the lore for my character I started with IW havoc, went through Slaanesh, Khorne and ended up with a Tzeentchian sorc (just as planned), I only skipped Nurgle for obvious reasons...they stink . Chaos is not limited by any bonds, especially not bonds of reason, we're not loyalists with their stupid Codex Astartes, we have imiagination and flexibility. This approach is even popular with the whole GW now, look at their current policy or the last TT edition changes.
I was originally very indecisive in picking a faction. Mainly I thought of Space wolves & Dark angels. DA are in, their color scheme was mostly the trigger for my interest. Their primarch is kinda meh. He handed Perturabo his hard won siege tanks, failed so bad he had to slumber in the rock, etc. There was a time when Chaos was easier to access on the servers, so naturally I started playing chaos. Played chaos ever since. Storm shields became a weird novelty to me when I tested them out recently. I'm kinda on the verge of staying in chaos' ranks. The inter-legion swapping kinda intrigues me. I recently listened to the audio book "Mark of Calth -The Underground war" Spoiler: Mark of Calth -The Underground war -It's about a Word bearer who fought at Calth and after 7 years of underground war without reinforcements from his legion, he decides to abandon the war & search for a way out from Calth on the irradiated surface while taking mementos from the fallen Word bearers to be remembered. I really liked it, since the story had a surprising ending with a good plot twist I really didn't see coming. I also liked the way it handled the daemonic possession, kinda like Argel Tal previously, where the Daemon is just a symbiotic entity, instead of actually fully possessing the host. -I really like the Horus Heresy era Alpha legion, but I dislike their image in the late 40k. I probably would just take Alpha Legion, but we'll see how they are portrayed in EC. -I'm also kinda intrigued by the Fallen. They could be a major plot element in Arkhona, since Belial is clearly there to stomp them out. (We can get a Fallen commander for Chaos, Belial commands the Loyalist forces...) I'm absolutely going to play with chaos at launch. Not sure if it'll be my main character, but we'll see. I'm also open for character background suggestions... A good background story might just be enough to tip the scales at this point.
I strongly recommend to all those who ever considered playing chaos, no matter Night Lords or not: the Aaron Dembski-Bowdens trilogy, now sold as a Omnibus: http://www.blacklibrary.com/all-products/night-lords-the-omnibus_.html This gives a juicy insight into the motivations and backgrounds of renegades fighting on the Chaos side. Both worshipers of Ruinous Powers, or like Talos - those that despise the gods. As to the latter I also strongly recommend the latest installment in Horus Heresy series: http://www.blacklibrary.com/all-products/pharos-ebook.html since it brings three very interesting characters to the lore: Kellendvar , Kellenkir and Skraivok that has inspiring motivations that drive them "away from the light of Emperor". I would call this trio: the rebel, the madman and the power-hungry If by any chance this (above-mentioned books) will persuade anyone to join VIII Legion warbands, then all the better!