Supporting characters can also be interesting to focus on. For example, a best friend of one of the main characters who might play a role in either bringing them together or causing misunderstandings. They can add more complexity to the story.
The two lead characters are obvious choices. Their relationship is at the heart of the story, so delving deeper into their personalities, backstories, and how they interact can make for a great fanfiction.
Even minor characters like a kind neighbor or a strict teacher can be given more importance in the fanfiction. Maybe the neighbor witnesses some key moments between the main characters and gives them advice, or the teacher's actions somehow influence the relationship between the two lovers.
Garroth is a character worth focusing on in 'crossover my street fanfiction'. He has a strong sense of loyalty and honor, which can be tested in a crossover situation. His relationship with Aphmau, whether it's a romantic or platonic one, can be a central point in the story. Dante is another character that can be great for crossovers. His laid - back attitude and his ability to get along with almost everyone can help bridge the gap between different groups of characters in a crossover. Plus, his skills in combat or other areas can come in handy depending on the nature of the crossover.
The main family members can be great to focus on. Their relationships, power struggles, and dreams offer a lot of material. For example, the patriarch of the family who has to make tough decisions to keep the ranch going. Another good character could be the strong - willed matriarch who holds the family together. Also, the young and rebellious heir who wants to do things his own way.
I don't have information about the main characters in this novel as it's not widely known to me. It could be a young couple, perhaps a man and a woman from different walks of life.
Sersi is a great character to focus on. She has a strong connection to humanity and her powers are quite interesting. You could explore her relationships with humans in more detail. Another good one is Ikaris. His loyalty and the internal conflict he might face are good material for a fanfiction. Then there's Kingo, with his love for movies and his unique charm among the Eternals.
All of the members of 4 town are great to focus on in different ways. Tae Young, for example, might be the subject of a fanfiction where his amazing dancing skills are the center of the story. Maybe he gets an offer to be in a big dance competition outside of the band, and he has to decide whether to take it or stay loyal to 4 town. Each member brings their own unique traits that can be explored in fanfiction.
Not having read the 'mu accidental love is you novel', we can only guess. It could be that the main characters are two individuals from different backgrounds. One might be a shy and introverted person, while the other is outgoing and adventurous. Their accidental encounter could lead to a love story that challenges their individual beliefs and lifestyles as they get to know each other better.
The friends of the main couple can also be great to focus on. They can add humor, support, or even create some conflict. For example, a friend who is always teasing the couple about their relationship can be a fun addition to the fanfiction.
Sebastian is a fun character to focus on. You can write about his loyalty to Ariel and how he tries to keep her out of trouble. He could have his own mini - adventures in a fanfiction, like getting lost in the human world while trying to find Ariel. Flounder is another good one. You could show his growth from a timid fish to a more brave friend of Ariel's. Also, Triton, Ariel's father, can be a central character. You can explore his relationship with Ariel in more detail, like his struggle to let her go.
In my opinion, Magnus Bane could be a great character to focus on in Clockwork Angel fanfiction. He has such a flamboyant personality and his magic abilities are quite interesting. He could interact with the main characters in ways that haven't been explored in the original story. Another good character would be Charlotte. As the head of the Institute, she has a lot of responsibilities and secrets that could be delved into. And of course, Tessa. She is the center of the story in many ways, and her character development is something that can be further explored in fanfiction.
Obviously, Bella herself is a great character to focus on. She's the main character and has so much potential for different storylines. You could explore her growth as a football player and as a person.