Zuko could be a main character. He might be the uncle figure to Azula's daughter, trying to guide her away from the dark path her mother once walked. He could share his own experiences of redemption and growth with her.
Aang could also be a key character. He might be seen as a symbol of peace and wisdom in the fanfiction. The daughter could either be in conflict with Aang's ideals because of her mother's history or be inspired by him to create a more harmonious world. Another possibility is Katara. She could be a mentor to the daughter, teaching her about the power of water - bending and the importance of compassion, which was something Azula lacked.
There could be new characters created specifically for the fanfiction. For example, a childhood friend of the daughter who has no connection to the original story's events but plays a crucial role in the daughter's life. This friend could be the one who supports her unconditionally, while she is struggling with her identity as Azula's daughter. Or perhaps an antagonist who blames the daughter for all of Azula's wrongdoings and tries to make her life miserable, creating a lot of drama and conflict in the story.
Fluttershy might be a key character. Her gentle and kind personality could have a big influence on Twilight's daughter. The daughter could learn about compassion and caring for animals from Fluttershy. And of course, Rarity could be in it too. Rarity could help the daughter with her appearance and self - confidence, perhaps creating some beautiful outfits for her.
There could be a group of friends she makes during her adventures. They could be from different backgrounds and have different skills. For example, one might be a healer, another a tracker. And of course, there could be characters from the existing ninja clans who either support or oppose her. Some of the clan leaders might play important roles as they have their own agendas regarding Madara's legacy. And then there could be a mysterious figure who seems to know more about her father's secrets than she does, and she has to figure out if this person is an ally or an enemy.
I think Naruto could be one of the main characters. Since he's Kakashi's student, he might have a special relationship with Kakashi's daughter too. Maybe he acts like an older brother to her.
There could be new characters created specifically for the fanfiction. For example, a mysterious old wizard who lives on the outskirts of Neverland and has knowledge about the daughter's true potential. Or a mermaid who befriends the daughter and helps her understand the secrets of the underwater world in Neverland. These new characters could add more depth and variety to the story.
Well, Boruto could be an interesting character. As her older brother, he could be a mentor figure to her, teaching her some of the more advanced ninja techniques he's learned. He could also be protective of her and get into trouble when he tries to defend her honor. Another character could be Sarada. She and Naruto and Hinata's daughter could become good friends, training together and sharing secrets about their families and dreams.
Well, it could be about the daughter inheriting Azula's fire - bending skills and facing the challenges of living up to her mother's legacy. Maybe she has to deal with the stigma attached to Azula's actions in the past while trying to find her own path in the world.
Edward Cullen himself is always a popular character. Fans love to see his fatherly side in these fanfictions. He's often depicted as overprotective yet also trying to give his daughter some freedom. Bella Swan, the mother, is also popular. Her relationship with her daughter and how she imparts her human experiences to the half - vampire daughter can be an interesting aspect. Another popular character could be Jacob Black. His interactions with the Cullen family might extend to the daughter, and his werewolf nature could create some unique storylines in relation to her.
Dumbledore could be an important character too. He might be aware of Snape's daughter's existence and see the potential in her relationship with Draco. He could be the one guiding them, or at least observing from afar, making sure their relationship doesn't cause any major disruptions in the wizarding world.
Boruto is often a popular character. Since he's Naruto's son, he has a natural connection to Naruto's daughter in these fanfictions. They might go on adventures together or have some sibling - like rivalries.
Severus Snape's memories or a ghostly apparition of him could be a main character. Since he had such a complex relationship with the dark lord, he could offer insights to the daughter. Also, Ginny Weasley could be significant. She's a strong witch in her own right and could be a role model for the dark lord's daughter. And then there are the professors at Hogwarts like McGonagall who would have to deal with the situation of having the dark lord's daughter at school.