A younger brother who is more shy and reserved compared to the others could be an interesting character to focus on. His experiences with the brides might be different from his more outgoing brothers. Maybe he has a hard time expressing his feelings at first, but as the story progresses, he opens up more. This character arc would be engaging to write about.
The eldest brother could be a great character to focus on. He's usually the leader among the brothers, so exploring his thoughts and decisions would be interesting. For example, how he decides which bride is right for which brother and how he manages the family as new brides come in.
One idea could be exploring the backstories of the brothers more in - depth. For example, how they learned their skills like hunting and building. Another could be a modern - day retelling of the story, with the brothers and brides in a contemporary setting, dealing with modern problems like technology and social media.
Percy himself would be a great choice. Since he's the main character in the original series, readers are already familiar with him. You could explore his relationships with his friends in more depth, like his loyalty to Annabeth and his brotherly bond with Grover.
Another option could be Ronald Speirs. His mysterious and tough - as - nails personality would make for an exciting character in a 'Kuroinu' - like setting. He could be the one who is not afraid to take on the most dangerous foes in 'Kuroinu' and his actions could drive the plot forward.
Ema Hinata is often a central character. Since she is the main female character in the original work, many fanfics tend to focus on her relationships with the brothers. Subaru Asahina is also quite popular. His passionate and sometimes brash personality can create interesting storylines in a lemon fanfic.
I think focusing on the Wattersons family as a whole can be really interesting in a Gumball fanfic. You can show their family dynamics, like how Richard's laziness affects the household, or how Nicole's strictness is both a help and a hindrance. Then there are the friends like Carrie, the ghost girl. Her spooky nature and her friendship with Gumball and the others can add a unique element to the story. And Tobias, with his one - sided crush on Penny, can also bring in some elements of unrequited love and jealousy into the fanfic.
Jack is a great character to focus on. He's the main character, so there's a lot of material to work with. His growth in martial arts and his relationships with the other characters are rich areas to explore. For example, you could write about his struggle to master a new move and how his friends help him.
Philip and Elizabeth Jennings are obvious choices. Their complex relationship and double lives are full of potential for fanfic exploration. You can create scenarios that further test their loyalty to each other and to their country.
One idea could be exploring the backstories of the brothers in more detail. Maybe each brother has a unique skill or talent that wasn't fully shown in the original. For example, the eldest brother could have been a great painter before they settled on the farm. Another idea is to write a fanfiction where the brides come from different regions, bringing their own cultures and traditions to the family, which could lead to some really fun and interesting interactions.
The main characters are always a great choice. Their pre - established relationships and storylines provide a solid foundation to build on. You can expand on their love story, or their struggles against the political backdrop of the story.
Definitely the main character's closest friends or allies. Their relationships can add depth and emotion to the fanfic. Also, antagonists are important. A well - developed villain can create conflict and tension. You can explore their motives and make them more than just a one - dimensional 'bad guy'. And don't forget about those characters who seem minor at first but have hidden potential or secrets.