The main theme is often corruption. The Death Guard are chaos-corrupted, and this is shown through their actions and the spread of the plague. Another theme is loyalty, in a twisted way. They are loyal to their chaos gods and to Mortarion.
Mortarion is also a central character. His journey from a Primarch to a servant of Nurgle is a major part of the story. His decisions and actions shape the fate of the Death Guard as a whole.
The Horus Heresy Death Guard novels are great reads. One of the things that stands out is the detailed descriptions of the battles. You can almost smell the stench of the Death Guard's plagues as they spread across the battlefield. These novels also explore the relationships within the legion, like the bond between the marines and their leaders, which is really interesting.
One popular black guard novel could be 'The Name of the Wind'. It features a complex protagonist with some 'black guard' - like traits at times. He is highly intelligent but also has a bit of a roguish side. Another might be 'Gentleman Bastards' series which is full of characters who operate in a morally grey area similar to what one might expect from black guard characters.
One popular 'death guard novel' is 'Plague War' which delves deep into the lore of the Death Guard. It shows their transformation into the chaos-corrupted warriors they are, with detailed descriptions of their battles and the spread of the plague. Another is 'Plague Garden' which further explores their dark nature and the way they operate within the Warhammer 40,000 universe.
One interesting plot point is the transformation of the Death Guard. Their fall from grace and their embrace of Nurgle's rot make for a dark and complex storyline. It shows how a once noble legion can be corrupted.
The uniqueness of Horus Heresy Death Guard novels lies in their portrayal of the fall. They show how a once - noble legion succumbs to chaos. It's a tragic yet engaging story.
Black guard novels often portray their characters as morally ambiguous. They might be anti - heroes who do bad things for good reasons or just for their own self - interest. For example, they could be thieves who steal from the rich but also keep some for themselves.
I recommend " From Ruins to the Roman Empire ". This is a historical novel. It mainly tells the story of the European continent that was baptized by the Black Death. It did not gradually become the center of the world like in history. Instead, it was struggling to survive under the threat of zombies. The bloodline withered, the crown fell, and the empire collapsed. In the ruins, a soul from the future silently descended into the world after the collapse. I hope you like my recommendation.😗