The Bones family would be important characters. Depending on how the fanfic is written, Amelia Bones could play a major role as she might be the one raising Harry. Other members of the Bones family, like cousins or aunts and uncles, could also be significant characters, influencing Harry's upbringing and his view of the wizarding world.
In this fanfic, perhaps there are new relationships that Harry forms. He might become friends with characters he didn't interact much with in the original story. For example, he could have a closer bond with some of the Bones family members and through them, gain new allies in the wizarding world. This could lead to different adventures and challenges that he has to face, like dealing with family politics within the Bones family.
Obviously, Harry Potter himself. And there could be some dark creatures or entities from Tartarus that act as his guardians or mentors in this strange upbringing. Maybe some sort of dark wizard who has made Tartarus his lair and takes Harry under his wing.
Obviously, Amelia Bones herself is a main character. Often, other characters from the Harry Potter universe can be main characters too, like Albus Dumbledore. He might be involved in plots with Amelia Bones, sharing wisdom or collaborating on important matters in the fanfic.
The main characters are likely Booth and Bones. Booth is probably the one who takes on the role of the savior, while Bones is the one in need of being saved.
It could be a dark wizard who has infiltrated the Ministry of Magic. This antagonist might be trying to undermine Amelia Bones' work and also target Harry for his fame and power.
The main characters are Bones and Galia. Bones, who is likely to be a complex character with his own set of values and emotions, is focused on getting the right engagement ring. He may have to overcome various obstacles in the process. Galia is the woman Bones loves, and she represents the future that Bones is looking forward to. Their relationship forms the core of the fanfic, and the engagement ring is just a symbol of their love and commitment in this story.
The main characters are, of course, Harry Potter and Susan Bones. Harry is the famous Boy - Who - Lived, known for his battles against Voldemort. Susan Bones is a Hufflepuff student, a bit of an under - the - radar character in the original series but with great potential in a fanfiction. She comes from a well - known wizarding family, and her inquisitive and kind nature could make for an interesting dynamic with Harry.
Well, obviously Bones Boy himself is a very popular character. He is the center of these fanfics after all. But often, his sidekicks or rivals can also be popular. For example, if there is a character who is always competing with Bones Boy in the original work, in fanfic they might have more complex relationships and become popular among readers.
Perhaps there's an antagonist, like a person from the orphanage who has some ulterior motives. Maybe this person doesn't want Bones to adopt the boy because they have other plans for the child. But Bones has to fight against this person to keep the boy.
Maybe there is a reclusive old hermit - like figure who has some connection to the house of bones. This character could have been living near the house for a long time and has some deep - seated knowledge about the origin of the bones and the secrets of the house. They could initially be reluctant to share their knowledge but eventually be persuaded to help the other characters.