I just completed the fourth and final medium-sized knight of my Dreadblade warband, and thought I'd celebrate by posting them here before moving on to the War Dogs!
The army is built for narrative play primarily (as you probably surmised from the presence of the Lancer... ouch) and as such has
plenty of background story, though I will spare you the long read - here's a brief summary:
As you can tell, the band is a mixed gathering of very different individuals, who range from seemingly uncorrupted to bearing dramatic signs of Chaos corruption, but they are united in their purpose against the Imperium. They are a former Freeblade lance who were caught up in political machinations after the Great Rift
appeared, and when one of them was framed, they chose loyalty to each other over loyalty to the Imperium. They will fight alongside the forces of Chaos towards the common goal of revenge against the Imperium, but they do not swear allegiance to it - though some would say at this point the distinction is rather moot.
As time has gone on, the pull of Chaos has wrought visible changes to some of them more than others, but for the moment at least they hold true to their oaths to one another, no matter what.