Percy Jackson would be an obvious choice. His skills as a demigod and his experience with different quests would make him a great character to be sent back in time. He could use his water powers in unique ways in different historical settings.
Apollo, in his demigod form, would be an interesting character to send back in time. He could use his musical and healing abilities in different ways. Also, his knowledge of the past as a god could add a lot of depth to the story, even if he has to deal with being in a more limited demigod form in a different time period.
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.
One idea could be that the demigods are sent back to prevent a great disaster that was actually caused by one of their own kind in the past. They have to figure out who it was and stop it without changing too much of the future.
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.
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.
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.
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.
Jiraiya is often a popular character in 'Naruto sent back in time fanfiction'. Since Naruto has a strong bond with him in the original series, in these time - travel stories, Naruto can learn even more from Jiraiya in the past and they can have new adventures together. Kakashi is also favored as he can be a mentor to Naruto in a different way with Naruto's new perspective.
Well, Hinata is often a popular character in these fanfictions. Since Naruto has a chance to redo things, his relationship with Hinata can start earlier or be developed in a more in - depth way. Jiraiya is also a favorite. Imagine Naruto going back and being able to spend more time with Jiraiya, learning even more from him. And of course, Itachi. Naruto could potentially change Itachi's fate, and fans love to explore this possibility in the fanfiction.
One possibility could be Percy Jackson as a demigod. He's well - known for his adventures in the demigod world. And for a wizard, Harry Potter could be a great choice. Their encounter would be really interesting as they both have very different personalities and ways of dealing with problems.
A son of Zeus could be a great demigod character. He has the power of lightning and is very strong and confident. As for the vampire, a centuries - old vampire who has seen a lot and is quite wise but also has a bit of a dark side. They could make for an interesting pair.