After looking at the Cult of Slaanesh Warhammer army list I got into wondering if such a thing could happen in 40k. The Dark Eldar commmit atrocities to stave off Slaanesh, but what if they go so far as to be corrupted by it, or are tainted by chaos in some other way? I think that at least a small number of Dark Eldar could fall to Chaos worship, or are they too selfish/entrenched in their ways to fall to the Dark Powers?