- live in an impenetrable fortress from which they launch raids on the innocent, never suffering the consequences of the evil they commit
- ruled by the most cruel and decadent amongst them, but don’t do anything about it because they dream of being on top of the horrific pyramid of torture and pain one day
- innately cruel and horrific society where seeing others suffer is the only source of pleasure
- slavers
- violence is the only language they understand
- sense of racial superiority
- entire sectors of society dedicated to coming up with evil and sadistic weaponry with which to commit war crimes
- hopelessly addicted to drugs of all kinds
- complete lack of compassion
- piracy
- love to torture
It fits too well. They supposedly formed an alliance with the tau to get the tyranid only to backstab them. Its dangerous to be the dark eldars enemy, fatal to be their friend.