Obviously, Surik herself is the central character. She is the focus of these stories.
Often, other Jedi characters may be featured. They could be her former masters or fellow Jedi who she interacts with. For instance, a story might include her old mentor who gives her some crucial advice during a difficult mission.
One interesting story could be about Surik's uncharted adventures in the outer rim. Maybe she discovers a lost Jedi temple with secrets long forgotten. It could involve her facing new and strange enemies, and using her unique skills to overcome them.
Darth Vader is often a main character. His menacing presence and complex character make him a favorite to explore further in fanfiction. Writers can delve into his inner thoughts and his relationship with the Emperor.
Clone troopers are often main characters. Since Umbara was a significant location in their story arcs, fanfiction might focus on their experiences, like Captain Rex leading his troops through the dangerous terrain and battles on Umbara.
Jedi are often main characters. Jedi like Obi - Wan Kenobi or Yoda might be the focus as they deal with the aftermath of Order 66. Also, clone troopers are common. Some fanfictions might feature a particular clone who has a change of heart during Order 66.
Some fanfictions in 'Brothers in Arms Star Wars' focus on new, original characters. For example, a young Jedi trainee and a smuggler who cross paths. The Jedi trainee is on a quest to find a lost Jedi artifact, and the smuggler has information about its whereabouts. As they journey together, they become brothers in arms, facing pirates, Sith assassins, and other perils.
Darth Vader also features a lot. There could be stories that go deeper into his past, perhaps his time as Anakin before he fully embraced the dark side. It could show his internal struggles in a new light.
One of the main characters is often Tyber Zann himself. He's a central figure in the Zann Consortium, so stories might revolve around his schemes and power plays. Another could be a rebel spy who infiltrates the consortium to gather intelligence.
Another character could be Kylo Ren. His internal conflict between the light and the dark is a rich area for exploration in fanfiction with the 'Shadows and Darkness' theme. Fanfic writers might focus on his early days of being seduced by the dark side, the shadows in his mind that led him to make certain choices.
Darth Vader is another main character. His menacing presence and his fall from grace as Anakin Skywalker are important aspects of the Star Wars lore. In the '5 minute star wars stories', his battles and his relationship with the Emperor might be told.
The clones are often main characters. They are the ones who execute Order 65, so fanfictions explore their motives and feelings. Some clones might be remorseful, while others are just following orders blindly.