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.
Lore can be seen as the back story. It might include details about the origins of a place, the past of characters, or the hidden histories that shape the current situation in a story or game.
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.
The Lore TV show is indeed fictionalized. It takes elements from various sources and weaves them into fictional narratives that may or may not have real-world inspirations, but are not based on actual events.
Fictional lore is basically the background story and world-building in a fictional setting. It's made up of details like history, culture, and rules. For example, in the Lord of the Rings, the lore includes the history of Middle-earth and the different races and their powers.