We could be young dark Eldar living on the mean streets (like theres any other kind) of the dark city and our struggle for survival and eventual forming a kabal and rising to power
Or we could be a band of kroot mercenaries roving the galaxy looking for work (and DNA variety)
Or we could be Eldar corsairs and raid imperials and do what ever the hell we feel like...maybe plunge into the eye of terror in search of crone worlds
Its limitless
