One possible plot could be that Jason Wayne, a lonely hero, meets the little girl at an event. He sees her in a difficult situation, like being bullied or orphaned. This sparks his protective instinct and he decides to adopt her. Then, he has to adjust his life to take care of a child, which includes learning about parenting and dealing with the girl's emotional needs.
Legal issues could be a major challenge. The adoption process can be complex, especially if there are issues with the girl's background or if Jason Wayne has any 'questionable' aspects in his own life according to the law. He may also face challenges within his own social circle. Some of his friends or colleagues might not be supportive of his decision, thinking it will interfere with his work or change his image. This could put a strain on his relationships as he tries to do what he believes is right for the little girl.
In the fanfiction, Batman might adopt the little girl because she shows extraordinary intelligence or a unique ability. For example, she could be a tech prodigy. This would attract Batman as he always looks for ways to enhance his crime - fighting capabilities. He would then have to balance his role as a father figure with his duties as Batman, which could lead to some interesting internal and external conflicts.
Another challenge could be dealing with the expectations of being Sanya Claus's adopted daughter. People in the magical world might have high hopes for her, and she has to learn quickly how to live up to those. For example, she may need to learn magic fast to participate in Christmas - related activities, like helping to make toys or flying the sleigh.
In this fanfiction, the plot might revolve around the little girl having some secrets or a special ability. Bones adopts her not knowing this at first. As they live together, the girl's secrets start to surface. This causes some tension but also draws them closer as they work through it together. Also, Bones' friends might be skeptical about the adoption at first but then come to love the girl.
Well, such a fanfiction could explore different themes. For example, the little girl might introduce Bones to a more emotional and carefree way of living. Bones, in turn, provides the girl with stability and protection. It could also involve Bones' friends or colleagues interacting with the girl, which may lead to some comical or touching moments. Maybe the girl has a special talent or interest that Bones helps to foster.
It's possible that the little girl's presence would soften Batman's tough exterior. He's always been this brooding, dark figure, but having a daughter - like figure in his life could make him more approachable and show a different side of him to the people of Gotham.
In this fanfiction, Sanya Claus could be on a mission to find a successor. He stumbles upon the little girl who has an unwavering belief in the magic of Christmas. Even though she is poor and has faced hardships, she always tries to spread cheer. Sanya Claus decides to adopt her and train her to be like him. As she grows, she faces challenges like learning how to use magic to deliver presents and dealing with naughty children. But with Sanya Claus's guidance, she overcomes these and eventually becomes a great helper, and maybe one day, the new Sanya Claus.
Well, it could start with the little girl being an orphan from a destroyed village. Naruto, having experienced similar pain, feels a strong connection. He adopts her and as she grows up, she becomes a source of pride for Naruto. She might also have some unique abilities that Naruto helps her develop while also protecting her from those who might want to use her powers for bad.
Obviously, Batman and Jason are the main characters. Batman is the mentor and adoptive father figure, while Jason is the young boy who is being taken under Batman's care.