Well, 'Leman Russ: The Great Wolf' is also among the best. It tells the story of Leman Russ, his leadership of the Space Wolves, and their unique place in the Imperium. 'Angron: Slave of Nuceria' is really good too. It shows Angron's tragic past on Nuceria and how it shaped him into the violent Primarch he became.
It depends on personal preferences. Some might consider Horus as the best for his complex character and role in the story.
Sure. 'Horus Rising' is a great start. It's easy to follow and it gives a good overview of the whole Horus Heresy concept and the character of Horus. It's sort of the starting point of a very big and complex story.
One of the great primarch novels is 'Magnus the Red: Master of Prospero'. It tells the story of Magnus and his relationship with his legion and the events that led to his actions during the Horus Heresy. Also, 'Angron: Slave of Nuceria' is popular as it shows the tragic past of Angron and how it shaped him into the primarch he became.
Magnus the Red is also an interesting choice. Given his connection to the warp and his fall from grace, there are many stories that can be told. Maybe a fanfiction where he tries to redeem himself in some way, or a story that delves deeper into his relationship with his father, the Emperor, before his downfall.
No. Although they are deeply rooted in the Warhammer 40K lore, the primarch novels can be appealing to a wider audience. The character development of the primarchs is quite detailed. For example, the story of how a primarch rises or falls can be interesting even to those who are not die - hard Warhammer 40K fans. There are elements of politics, war, and personal struggle that can engage readers outside of the core fanbase.
I'm not entirely sure as I haven't read it in detail. But generally, it might be about the journey, battles, and character development of Alpharius as a primarch.
One main theme is power. Combining the powerful abilities in Naruto with the might of the Primarchs often leads to exploring different levels and types of power. Another theme is identity. Characters may struggle with their new identities when influenced by Primarch - like qualities.
There are fanfictions that focus on the Primarch Magnus the Red. For example, a story could be set during his time on Prospero, delving into his study of the warp and how his actions were misinterpreted by the Imperium. It could also show his complex personality and his love for knowledge.
In this type of fanfiction, the main characters associated with the 11th Primarch can vary widely. There could be Inquisitors who are either investigating the 11th Primarch or working with him. These Inquisitors could bring their own motives and agendas. Tech - Priests might also be important characters as they could be interested in any new technology or knowledge that the 11th Primarch might possess. And of course, there could be Chaos Lords who see the 11th Primarch as a threat or an opportunity for their own dark purposes.
One great 'oc primarch fanfiction' story could be one where the oc primarch has unique powers that set them apart from the traditional ones. For example, a primarch with the ability to control time on a small scale, which adds a really interesting dynamic to the battles and political intrigue in the Warhammer 40k universe. Another good one might be a story where the oc primarch has to deal with being an outcast among their own brethren due to their unorthodox views and methods.