Lelouch could be involved. Since he's always been at the center of power struggles in Code Geass, he might see the re - found Fleija as a tool to further his goals of overthrowing Britannia or protecting those he cares about.
In such a fanfic, perhaps the rediscovery of Fleija could lead to a new power struggle. Different factions might try to gain control of it for their own purposes, like the Black Knights or the Britannian military.
Kallen could also be involved. She has a strong and fiery personality. A tickle fanfic could explore a more vulnerable and fun - loving side of her. Maybe her friends try to tickle her to get her to relax after a tough battle.
Lelouch is a very likely candidate. Given his intelligence and his desire to change the world, time travel could be a means for him to correct past mistakes or gain more power to overthrow Britannia. Another one could be Suzaku. He has a strong sense of justice and might use time travel to prevent some of the tragedies that occurred.
Lelouch is often still a central figure. His complex character and his journey of trying to change the world make him a favorite to explore further in fanfics. Writers can take his story in new directions, such as showing his life after achieving his goals in different scenarios.
A fanfic about Cornelia could be a character study. It could delve into her past, like her upbringing in the imperial family and how that shaped her into the strong - willed person she is. Maybe it could also show her softer side that she doesn't often display in the anime.
In Code Geass fanfic, Nunnally is often a complex character. She is usually depicted as a symbol of innocence and hope. Writers might explore her relationship with Lelouch in different ways. For example, some fanfics might focus on how she would react if she knew all of Lelouch's secrets and plans. Her blindness also adds an interesting layer to her character, as it can be used to show her inner strength and vulnerability simultaneously.
The 'Code Geass 5 Year Fanfic' might expand on the original world - building by delving deeper into the politics of the different nations. For example, it could explore how Britannia's rule has changed over the five years, whether there are new rebellions brewing in different regions. It may also focus on the economic aspects. Maybe some regions are suffering more due to Britannia's policies, and this leads to new forms of resistance.
Fanfics often take on different genres as well. Some Code Geass Code Fanfic are action - packed adventures that take the characters on new quests outside of the original storyline. Others could be more of a mystery, where the characters have to solve a complex problem that was not part of the original plot. And then there are the ones that are more character - driven, focusing on the emotional growth and development of the characters.
In 'Code Geass Sequel Fanfic', Lelouch remains a top pick among fans. His intelligence and ability to manipulate situations are always interesting to write about. C.C. is popular not only because of her connection to Lelouch but also because of her immortality and the secrets she holds. Another character that gets a lot of attention is Schneizel. His strategic mind and his role in the political landscape of the Code Geass world make him a character that can be explored further in sequel fanfics. And of course, fan - created characters that interact with the original cast in unique ways can also become very popular.
I'm not sure which characters are the main ones in this particular fanfic. It could be Lelouch, as he is a central character in the original Code Geass series. Maybe it also includes C.C., who has a significant role in the story. But without reading it, it's hard to say for sure.