The psykers can also be main characters. Psykers have psychic powers which are both a great asset and a huge danger. In the short stories, they might be struggling to control their powers while also being used by the Imperium in various ways.
The Space Marines are often main characters. They are genetically enhanced super - soldiers, highly trained and loyal to the Imperium. They come in different chapters, each with its own specialties and traditions.
The short stories about the Orks can also be really engaging. Orks are known for their brute strength and love for fighting. In these animated short stories, we might see their wacky and violent battles, like when they raid a human outpost just for the fun of it. They have a unique culture that makes their stories stand out.
The Space Marines are very common main characters. They are genetically enhanced super - soldiers, and their stories often revolve around their missions to protect the Imperium.
One of the main characters is Ciaphas Cain. He is from the 'Gaunt's Ghosts' series. He is a bit of a reluctant hero, always getting into and out of trouble in the most interesting ways.
The Empress herself is of course a main character. Often, you'll also find Space Marines, as they are a significant part of the Warhammer 40k universe and interact with the Empress in various ways. Imperial Guardsmen may also be present, depending on the plot of the fanfiction.
I don't know for sure, but it could be the Space Marines. They are often central characters in Warhammer 40k stories.
One popular character is Marneus Calgar. He is a powerful Space Marine Chapter Master. Another is Commissar Yarrick, known for his tenacity against the Orks. And there's also Abaddon the Despoiler, a major Chaos figure.
In the Warhammer 40k War of Secrets novel, it's possible that there are main characters from different factions. There might be a tech - priest from the Adeptus Mechanicus who is trying to unlock some technological secrets. Or perhaps a Commissar who is involved in uncovering some political secrets within the Imperium. There could also be a Chaos cultist whose actions drive part of the story as the Imperium tries to root them out.
A Vampire Lord from a long - lost dynasty could be a main character. He might be trying to reclaim his former glory in the 40k universe filled with so many powerful factions.
In many of the novels, Asdrubael Vect is a significant character. He is a powerful and cunning leader within the Dark Eldar society.
In 'The Knight of Talassar', Sir Hekhtur is a main character. He is a noble and skilled Imperial Knight who has to face various challenges. His character is well - developed, and we see his growth throughout the story.