Dark Eldar
"Think occasionally of the suffering of which you spare yourself the sight." - Albert Schweitzer
The Dark Eldar are the villainous counterparts of the Eldar, who followed the horrific depravity that saw the Eldar Empire destroyed. Hailing from Port Commorragh in the Webway, the Dark Eldar spirit out from the shadows to take slaves to commit unspeakable atrocities on whoever they capture.
In short, they're the most evil race in Warhammer 40,000, which is a hell of an accomplishment. Their lives revolve around sadistic torture, making them a sort of cross between the cenobites from hellraiser and the reavers from fireflly. They are mainly pirates, though are sometimes used as mercenaries.