Obviously, Minato would be one of the main characters. Naruto would also be a central figure as Minato's son. Sakura and Sasuke might also play important roles, as they are Naruto's friends and comrades. Kakashi, who was Minato's student, could also be a major character.
In 'Naruto second Orochimaru fanfiction', Orochimaru is the central figure. Alongside him, Kabuto might be a prominent character as he was Orochimaru's right - hand man. Another character that could play a major role is Sakura. Since she is part of Team 7 with Naruto and Sasuke, and any threat or plot involving Orochimaru would likely draw her in. Also, there could be new characters created specifically for this fanfiction that interact closely with Orochimaru.
Well, it could be about Minato being brought back to life and having to deal with the new threats in the Naruto world. Maybe he has to face off against new and powerful enemies that his son Naruto and the others are struggling with.
The Hokage, whether it's Tsunade or others, would also be main characters. Since Naruto's actions often have a big impact on the village leadership and vice versa. With a second chance, Naruto's interactions with the Hokage could lead to different policies and decisions for the Hidden Leaf Village, making the Hokage an important part of the story.
Another possibility is that the fanfiction could introduce new characters who play a major role in the 'coming home' story. They could be new vampires or humans who have a connection to the original Twilight characters. For instance, a new vampire who was turned while Bella was away and now she has to deal with this new presence when she comes home, and this new character could bring a whole new set of conflicts and relationships into the story.
Obviously, Team Minato itself is the main focus. This includes Minato Namikaze, who is the leader of the team. He is a very powerful ninja with his Flying Thunder God Technique. Then there's Kakashi Hatake, a young and talented ninja who is known for his Sharingan. Obito Uchiha is also a key character, with his Uchiha blood and his dreams of becoming Hokage. And finally, Rin Nohara, who plays an important role in the team's dynamics.
Obviously, Team Minato itself would be the main characters. That includes Minato Namikaze, Obito Uchiha, Rin Nohara and Kakashi Hatake. They are the core of this story as it's about them watching the future.
Perhaps some rogue ninja from other villages. They might see Naruto as a symbol of Konoha's power and want to take him down to weaken Konoha. These rogue ninjas could be led by a powerful and vengeful shinobi who has a grudge against Konoha. So when Naruto is alone on a mission or something, they attack, and that's when Minato steps in to save him.
Sakura could be another main character. She might be shocked by Naruto's arrest and start her own investigation. Maybe she teams up with Sasuke, who also has his own complex feelings towards Naruto. Their combined efforts could play an important role in uncovering the truth.
Obviously, the Yellow Flash is one of the main characters. He is the center of the 'Second Coming' concept. There might also be his former comrades or friends who were part of his story before his first 'departure'.
Sakura could be a significant character. In the context of Naruto being Minato's son, her relationship with Naruto might change. She could be more in awe of him at first or have different expectations. Also, Sasuke is likely to be a main character. His rivalry with Naruto could take on new dimensions as Naruto has the added legacy of being Minato's son. Their battles and interactions might be more intense and influenced by Naruto's heritage.