I'm not sure specifically as it depends on the fanfic. It could be new characters created by the fanfic author who are descendants of the well - known Star Wars characters. For example, a grandchild of Luke Skywalker might be a main character, carrying on the Skywalker legacy in new ways.
It could also feature some of the classic characters in different roles. Maybe Han Solo is now a mentor figure to a new generation of smugglers. Or Princess Leia could be in a position of galactic leadership, making important decisions for the future of the galaxy. There might also be characters from species that haven't had much spotlight before taking on important roles in this fanfic's future setting.
A young Jedi apprentice who is curious about the future and goes on a quest to discover what lies ahead could be a main character. Also, an old, wise Sith lord who has lived through many eras and has a unique perspective on the future.
There's no way to know precisely without reading the 'watching the future fanfic'. But generally, there could be a group of friends or comrades who are facing the challenges of the future together. One of them could be a leader - type character with strong leadership skills. There might also be antagonists, perhaps those who want to control the future for their own selfish gains or those who oppose the positive changes that the main characters are trying to bring about.
One interesting idea could be new interpretations of the Force. Maybe it shows a future where the understanding of the Force evolves in unexpected ways, like new Force powers or different ways of training Jedi.
Maybe a young, aspiring Jedi who is trying to make a name for himself in a post - Empire galaxy. He could be from a species we haven't seen much of in the Star Wars universe before.
The reaction of Star Wars characters to watching the future in fanfiction would vary greatly. Consider Obi - Wan Kenobi. He would be calm and analytical, trying to understand the different paths the future could take. He might be looking for signs of the Force's influence and how he could help guide the right choices. And the stormtroopers? They might be confused at first, as they are used to following orders, but then some might start to question their roles in the future if they see a different way of life or a more just society.
One aspect could be the Rebels' reactions to the complex political situations in the Clone Wars. They might be shocked or inspired by the different alliances and betrayals that took place. It could also show how the Clone Wars era influenced the technology and weaponry available during the Rebels' time, like how the Rebels might see the evolution of starfighters from the Clone Wars to their era.
Well, it's likely that Eren would still be one of the main characters. After all, he's a central figure in the original 'Attack on Titan' story. He might be the one most affected by seeing the future and could play a crucial role in trying to change it.
Kylo Ren could also be a main character, even if he's dead in the official story. Fanfiction has the freedom to bring him back in some form, like as a Force ghost or through some time - travel shenanigans. Another possibility is Finn. He has grown so much throughout the movies and could have an important role in the future of the galaxy in this fanfiction.
The Ones themselves are obviously main characters in such fanfics. They have their own personalities and motives that drive the story. There might also be an old and wise Jedi Master who serves as a guide to the character involved with The Ones. This Jedi Master has knowledge about The Ones from ancient Jedi lore and helps the young character understand the significance of their encounter.
In the 'abeloth star wars fanfic', the main characters could include Abeloth, of course. There may be some original characters created by the fanfic author. However, it's also possible to see well - known Star Wars characters like Luke Skywalker or Darth Vader in some form, especially if the story is set in a timeline where their presence makes sense. For example, if it's a story set during the time of the Old Republic, we might see characters like Revan or Bastila Shan interacting with Abeloth.