The Empire builds its pride on the charge of its knightly orders; the Chaos Knights exist to demonstrate what that idea becomes when the Dark Gods take an interest. Horse and rider are armoured as one in fused black plate, and the steeds themselves are predators of the Wastes' breeding — fanged, ember-eyed things that eat what they trample. A formed charge of Chaos Knights has yet to meet a line of mortal infantry it could not open like a door.
The steed is itself a gift, granted only to warriors whose deeds have earned more than iron. Bonded rider and mount share a damnation as much as a saddle: the beast is as sworn to the Powers as the man, and northern sagas do not always agree on which of the pair is the more willing servant. Knights ride at the head of warbands as their champion's fist, and where they pass, the tribes say the gods ride close behind.