The main characters would be Ash, along with the Rocket trio which consists of Jessie, James, and Meowth.
Well, perhaps they could have amazing adventures together. The Rocket trio might learn valuable lessons from Ash and his friends. They could form an unlikely but strong bond, helping each other out in battles and exploring new regions.
Jessie and James are the obvious ones. They are the main members of Team Rocket. Jessie could be constantly trying to outdo Ash in Pokémon battles or contests of skill. James, on the other hand, might be more conflicted about having Ash around. He could secretly admire Ash's kindness towards Pokémon and start to have second thoughts about their Team Rocket activities.
They could also change Team Rocket for the better. Maybe they would introduce a new sense of honor or fairness. Ash's determination and Misty's feistiness could influence the other members to be less about pure evil and more about having fun in their villainous deeds. In a fanfiction, this could lead to some really interesting character development for both Ash, Misty and the Team Rocket crew.
Obviously, Ash and Dawn are main characters. Ash is the hero who comes to Dawn's rescue. Dawn is the one in need of being saved from Team Rocket. And of course, Team Rocket themselves are also important characters in this fanfiction as they are the antagonists.
Latios would obviously be a key character. Also, Pikachu, Ash's loyal Pokémon partner, would be there. Maybe Misty or Brock could also be part of the story, with them either supporting or being skeptical of Ash's newfound admiration for Latios.
A young girl named Mia might be a character too. She is also a Glacion fan and is very competitive. She challenges Ash to various Glacion - related challenges, like a Glacion knowledge quiz or a race to find a hidden Glacion item in the forest.
Obviously, Ash (as a girl) would be the main character. Pikachu would still be by her side, being her loyal and cute partner. Her friends like Brock and Misty would also be important characters. Brock might be even more protective of her now, and Misty could become a sort of role model for her in some ways.
Obviously, Ash and Jessie, James, and Meowth from Team Rocket are the most popular. Ash is the main hero, and the Team Rocket trio is always causing trouble for him, so they are central to most fanfictions in this theme.
I'm not sure specifically who the main characters are in Rocket Academy Fanfiction as it depends on the individual stories written by fans. But it could be students, teachers, or even administrative staff within the Rocket Academy.
Ash is obviously one of the most popular characters. He's the main character of the Pokemon anime, and in fanfictions, his adventures with or against Team Rocket are always interesting. People like to see how he reacts to different situations that Team Rocket creates or how he manages to outwit them.