One character could be a time - keeper or a wizard who has the power to send Percy back in time. This character could be an old and wise figure, full of knowledge about the past and the ways of time travel. Another could be a historical figure that Percy meets in the past. For example, a famous warrior or a philosopher who becomes Percy's ally or mentor.
There could be a love interest for Percy in the past. It could be a local girl from the era he's sent to, who is kind - hearted and brave. She might initially be curious about Percy, seeing as he's so different from the people of her time. And then there's always the possibility of a villain in the past. Maybe a power - hungry noble or a dark sorcerer who sees Percy as a threat to his plans and tries to stop him from achieving whatever he needs to do in the past.
It could be that Percy's friends from his own time somehow also get involved in the time - travel situation, either accidentally or on purpose. So we could have Annabeth or Grover also end up in the past with Percy. Or there could be a character in the past who is a seer or a prophetess. She could foresee Percy's arrival and either help or hinder him depending on her own motives and the prophecies she has seen.
Obviously, Percy is one of the main characters. But there could be others depending on the specific plot of the fanfiction. Maybe there are some characters from Percy's past that play important roles.
The plot might involve Percy going back in time and getting involved in a love story that was lost to history. He could fall in love with someone from the past and then have to make a difficult choice when it comes time to return to his own time. It could also be that he has to use his modern knowledge to solve problems in the past that no one else could figure out, which then changes the course of history in small but significant ways.
Well, Percy is obviously one of the main characters since it's about him getting sent back in time. There might also be his friends like Annabeth. In the past, he could meet characters who are important in the history of his world, like the ancient gods or heroes. They would play significant roles in his journey back in time as he might need their help or they could be obstacles in his way.
Perhaps Percy will discover secrets about his family or his powers that were previously unknown. Since he's in the past, there could be ancient magic or knowledge that he stumbles upon. This newfound knowledge could give him an edge when he returns to his own time, if he ever does. He might also face challenges like trying to blend in with the people of the past, as his modern ways could make him stand out and cause suspicion.
Grover could also be a main character. He might be at the scene when Percy gets drunk and try to use his nature - related powers to sober Percy up. Grover could also provide some comical relief with his reactions to Percy's drunken state, like his horrified expressions or his attempts to herd Percy like he would a wild animal.
Obviously, Naruto himself is the main character as he is the one sent back in time. Sasuke is also often involved as Naruto's relationship with him is a central part of the Naruto story. Kakashi could be involved too, as Naruto might seek his help or try to influence his training methods. Also, the various Hokages might be important characters as Naruto could interact with them in the past to change the course of events.
It could be an ancient and powerful Titan who was thought to be defeated long ago. Since Percy is in the past, this Titan could be in his prime and see Percy as a threat to his plans of ruling over the world again. For example, Kronos might be even more powerful in this past era and Percy has to find a way to stop him without the help of his modern - day friends.
There could be a rival within the family. Someone who wants Percy out of the way, perhaps for inheritance reasons or because they're jealous of Percy's abilities or popularity. This rival could be the one who instigates the events that lead to Percy's disownment. And then there might be a mentor - like figure outside of the family who takes Percy in after he's disowned and helps him to grow and face his new situation.
Well, perhaps a major plot twist is when Percy goes back in time and realizes that the events he thought were accidents in his own time were actually carefully orchestrated by a character from the past. This would add a whole new layer of mystery and conspiracy. Also, he might find that a prophecy he was trying to prevent in his time was actually meant to happen in the past for a greater good, which would be a huge turn for his mission.
It's possible. There could be other demigods or mythical creatures. Maybe a centaur who gives Percy some advice regarding the naiads. Or a sea monster that they have to face together.