One possible character development is that Harry could become more empathetic towards Bellatrix. He might start to understand why she became a Death Eater, considering her family background. Bellatrix could also become more protective of Harry in a strange way. She might try to shield him from Voldemort's wrath while still maintaining her loyalty to the Dark Lord on the surface. Additionally, this relationship could make Harry more isolated from some of his friends who are wary of Bellatrix. And Bellatrix could find herself in a very difficult position within the Death Eater ranks, as her connection to Harry might be seen as a threat to Voldemort's cause.
For Harry, he could develop a new sense of family obligation. He might try to reach out to Bellatrix in some way, hoping to turn her away from the dark side. Bellatrix could experience a transformation in her character. Maybe she starts to see Harry as more than just an enemy, and this could lead to her slowly breaking away from Voldemort's control. Another possibility is that other characters in the story, like Hermione and Ron, might view Harry differently because of this new relationship with Bellatrix.
Harry might become more conflicted. Knowing Bellatrix is his aunt could make him question his own identity and his place in the wizarding world. Bellatrix, on the other hand, could start to have doubts about her loyalty to Voldemort. This new family connection might tug at her conscience, if she has any left.
For Harry, he could become more desperate and resourceful. The experience of being captured by Bellatrix might make him more aware of the true nature of the dark side. He could also develop a deeper understanding of the Death Eaters' motives. As for Bellatrix, she might start to see Harry not just as an enemy but as a worthy opponent. This could lead to a strange sort of respect for him, or it could make her even more determined to break him.
For Bellatrix, she could start to question her loyalty to Voldemort. Her interactions with Harry might make her realize that there's more to the world than just blindly following the Dark Lord. As for Harry, he could become more aware of the true nature of the Death Eaters at a very young age, which would shape his future battles. He might also develop a sense of pity for Bellatrix in a way, understanding that she's a victim of Voldemort's ideology too.
Harry might start off as a confused character, not understanding his new identity. As he trains and learns more about Obito's world, he could become more confident in his abilities. He may develop a stronger sense of justice, influenced by both his wizarding world values and Obito's own complex view of right and wrong. Obito himself could also change, becoming more selfless as he tries to protect Harry and guide him.
Harry might become more understanding of the Slytherin side. Lucius could start to question his loyalty to the Dark Lord. For example, Harry's influence could make Lucius see the harm in Voldemort's actions.
Dudley could start to see Harry in a new light. He might realize that Harry's magical abilities are not just something to be feared or envied, but can be useful. For instance, when they are running from danger, Harry uses a spell to create a shield, and Dudley is in awe. This could lead to Dudley becoming more accepting of Harry and his world.
In this type of fanfiction, Harry's character development could be quite complex. As a submissive mate, he may initially struggle with the loss of some of his independence. But over time, he might find new strengths within this relationship. He could become more attuned to Snape's needs and emotions, which in turn could make him a more perceptive person. Snape, on the other hand, may start to open up more. His relationship with Harry could force him to confront his own feelings and biases. He may become less bitter and more accepting, not just of Harry but also of the idea that things can change and relationships can be different from what he expected.
For Harry, he may become more patient and obedient as he adapts to the role. He might also gain a new perspective on Snape. Snape, on the other hand, could become more protective and perhaps less harsh in his exterior.
Maybe it was a last - minute decision by James and Lily. They might have thought that having Bellatrix as a godmother would offer some kind of protection. After all, she was a powerful witch. Or perhaps there was some sort of old family pact or agreement that made her the godmother.
One possible plotline could be that Bellatrix captures Harry during one of his adventures and decides to keep him as a pet for her own amusement. She might use dark magic to bind him and make him obey her commands. Another could be that in an alternate reality, Harry is somehow magically enslaved to Bellatrix from the start, and the story follows his attempts to break free from her control while she uses him for various dark purposes, like spying on the Order of the Phoenix.
A possible plotline could start with Bellatrix having a strange fascination with Harry from the start. She manages to get him in her clutches and treats him like a pet. Harry, on the other hand, uses his wits and the limited magic he can access in this state to outsmart Bellatrix. There could be a lot of psychological battles between them, with Harry trying to understand Bellatrix's twisted mind while she tries to break his spirit. And all this could be set against the backdrop of the ongoing war between the good and the evil in the wizarding world.