[quote=@Seirei No Hai]
<Snipped quote by Dead Cruiser>

So like an atheist cult spread across Elysia that believes that The One isn't what their former kin believe it to be? Or did they find some other divine/demonic being they could worship in its place because whatever they are promises better in comparison?
[/quote]

All of the above. My basic idea is, the Astoriel being so ancient and prolific, they've had numerous fractures and reformations that have created splinter groups or seceding states. Thus the "Dark Elves" (working name at the moment: "Svariel") are just a catchall for members of their race that are outside the Enclave.