Main Characters Likely to exist:
Main Protagonists:
Eragon: I would be surprised if Eragon wasn't in the game as he is literally the protagonist of the books. He's the first person to bind to a dragon since the fall of dragons.
Roran: Leader of the Caravahall resistence, Eragon's cousing. A complete Fvcking badass and my favorite character in the books. "Stronghammer". Wields a basic blacksmith hammer but destroys everything he comes into contact with. Doesn't have powers like Eragon to be a complete badass.
Saphira: Eragon's dragon, can communicate with him telepathically. Can do basically anything a dragon can do. Likely in the game.
Brom: Brom is like the Gandalf of this series, there is a very high chance he is in the game. He teaches Eragon Magic, and mentors him. It's also later revealed that he is actually Eragon's father as a big plot twist. He dies fairly early on in the first book, but is still likely to be in the game with how prominent he is.
Arya: Eragon's love interest, she is the daughter of Queen Islanzadi.She accompanies Eragon through most of his adventures. I think she rejects him due to an age gap initially despite having feelings for him. She is like 100s of years old of and hes literally a prebuscent teenager. She's a badass in combat too if I remember correctly.
Big Side Characters:
Orik- King of dwarves
Oromis- Eragon's second mentor
Nasuada- Daughter of Ajihad, leader of the Varden after he father dies.
Angela- A Fortune telling time space and dimension traveling witch, who has a cat and gives Eragon a big hint to his future early in book 1.
Antagonists:
Murtagh- Would probably be considered more of a third party, he is forced to do everything for Galbatorix, rather than willingly. Maybe a miller, though hes the primary antagonist in the second and third book if I remember correctly.
Morzan- Last of the Forsworn
Ra'zac- Two bird like hunter things Eragon is chasing throughout the first book
The Twins- Two bald bad guys who betray the varden
Galbatorix- The main bad guy, surprisingly seen very little in the books til the very end.
I know I am missing a lot, these are largely based on memory, but there are a few side characters who I could see being in the game, maybe some of the Carvahall gang, or some of the Varden's elite warriors. I might listen to a youtube video to freshen up on these characters cuz I know I am missing a few