Raoul could also be an ally. Despite his past with the Phantom, he might see the daughter as an innocent and want to help her. He could use his influence in society to shield her from the negative attention that might come her way once her identity is known.
The stagehands and workers at the opera house could be allies. They have a connection to the place where the Phantom once held sway. They might be sympathetic to the daughter, especially if they had any positive experiences or secret alliances with her father. They could help her hide or provide her with information about the opera house's hidden passages and secrets.
An OC could be a young ballerina who has always been in the background but has a big heart. She could befriend the Phantom when she discovers him hiding in the rafters one day. Another could be an old janitor who has worked at the opera house for decades and has his own stories about the Phantom.
The Straw Hat Pirates could be great allies. Luffy is always open to new friends and they could help her with her goals. Another could be Trafalgar Law. His skills and his own motives might align with hers at some point.
Sam and Tucker would definitely be his top allies. They've been with Danny through his whole journey as a half - ghost, and they'd support him in his new role as the Master of Death. Sam could offer her unique perspective on the moral and ethical side of things, while Tucker could use his tech skills to help Danny understand any new powers or situations related to his new title.
One potential antagonist could be the new owner of the opera house. He might see Erik as a threat to his business and the safety of his performers, especially if Erik has been causing disruptions in the past. When Erik is injured, he could try to take advantage of his weakened state to get rid of him once and for all.
There's also a possibility of her allying with some of the more neutral houses. Houses that were tired of the constant fighting between the big players. Her daughter could offer them stability and protection in exchange for their loyalty. She could present herself as a new hope for a more peaceful Westeros, which might attract these houses to her side.
Luke Skywalker would be a great ally. Since he was also trained in the ways of the Jedi by Obi - Wan, he would likely feel a connection to Obi - Wan's daughter. He could offer her guidance in using the Force and share his own experiences. Another potential ally could be Chewbacca. He's loyal and strong, and his knowledge of the galaxy could be very useful for her. He could help her travel safely through different planets.
The Teen Titans could be potential allies. They are known for giving second chances and helping those who want to turn their lives around. If Deathstroke's daughter shows that she wants to be different from her father, they might take her in and help her develop her powers for good.
There's also a possibility that some of the more morally grey characters in Gotham, like Catwoman, could be Bella's allies. Catwoman has her own code of ethics, and she might relate to Bella's struggle between good and evil. They could work together in certain situations, especially if there are mutual benefits involved.
One common theme is the daughter's exploration of the mystery surrounding the Phantom. Since the Phantom is such an enigma in the original story, in fanfiction, the daughter often takes it upon herself to uncover the truth about him.
In some fanfictions, the daughter is depicted as a strong - willed character who decides to bridge the gap between the Phantom and the people of the opera house. She could start by secretly leaving messages for the Phantom, expressing her admiration for his music while also gently suggesting that he could co - exist more peacefully with the others. As time passes, she gradually brings the two worlds closer together.