One possible plot could be that Harry discovers this long - lost family connection after some mysterious event. Maybe he finds a hidden letter or an old family heirloom that reveals the truth. This discovery could throw him into an identity crisis as he has to come to terms with being related to a Death Eater. He might then try to find out more about his family's past and his connection to Bellatrix, which could lead him into dangerous situations as he delves deeper into the dark secrets of his family.
The plot could start with Bellatrix having a secret past that she has kept hidden even from Voldemort. Harry, on the other hand, has always felt a strange pull towards the Lestranges' story. As he uncovers the truth that he is Bellatrix's brother, he is faced with a choice. Does he embrace this new - found family connection and try to redeem Bellatrix, or does he keep it a secret and continue to fight against the Death Eaters? Along the way, he could meet other family members who are either supportive or try to use him for their own gains.
Yes, there might be such fanfiction out there. The Harry Potter fandom is vast and full of creative interpretations. Some fans like to explore unusual family relationships in their fan - created stories. This concept could lead to very interesting plotlines, like how it would change the dynamics between Harry and the Death Eaters if he was related to Bellatrix in this way.
One possible plot could be that Harry discovers a powerful and dark magic spell that allows him to gain control over Bellatrix. He then uses this to his advantage to gather information about Voldemort's plans from her. Harry might struggle with the moral implications of enslaving someone, even a Death Eater like Bellatrix.
One possible plot could be that Bellatrix, in a strange turn of events, decides to train Harry in the Dark Arts not to turn him evil but to make him a more formidable opponent against Voldemort. She might see his potential and think that by teaching him some of the Dark Arts, he can better understand Voldemort's tactics.
Well, perhaps Bellatrix was under some sort of spell or coercion when she had Harry. In the fanfiction, Harry might start having strange visions or powers related to Bellatrix's dark magic. As he enters Hogwarts, he is constantly suspected by Dumbledore and the Order of the Phoenix because of his connection to Bellatrix. But Harry, being Harry, still wants to fight against Voldemort, which creates a complex web of relationships and power struggles within the wizarding world. He may also try to find out more about his mother's past and what really happened when he was born.
It would be very strange and interesting. It might involve a complete rewrite of the backstories. Maybe there would be a hidden family connection that was somehow overlooked in the original story. Harry's character might have some of Bellatrix's traits, like her fierceness or her loyalty (albeit to different sides in the original story).
In a 'Harry Potter Saves Bellatrix' fanfiction, perhaps Bellatrix is in a situation where she's about to be killed by other Death Eaters who think she's a liability. Harry, having a sense of justice and seeing the potential for redemption in her, steps in to save her. He could then try to show her the error of her ways, using his own experiences of losing loved ones to Voldemort's ideology. Bellatrix might initially resist, but gradually come to understand Harry's point of view.
In some fanfictions, Bellatrix might kidnap Harry with the intention of turning him to the dark side. She could try to corrupt him by showing him the power and 'glory' of the dark magic she practices. This would be a huge psychological battle for Harry as he has always been firmly against the dark arts.
The plot could revolve around Bellatrix's memories in Azkaban. Since she was there for a long time, she might have had some extremely vivid and disturbing memories. A fanfiction could explore these memories and how they influenced her actions after she escaped. For example, she might have seen the faces of those she killed in her dreams while in Azkaban, and this could have made her more vengeful.
One possible plot could be that Harry discovers his true identity as Superman's brother. He might have been separated from Superman at birth for some reason, like a threat to their family. Then, as he grows up in the wizarding world, he starts to show some superhuman abilities which he doesn't understand at first. Eventually, through a series of events, he meets Superman and they realize their connection. Together, they use their combined powers of magic and super - strength to fight a common enemy that threatens both the wizarding world and Metropolis.
One possible plot could be that Harry discovers his long - lost brother Carlisle. This could lead to a journey where Harry has to adapt to the vampire world that Carlisle is part of, while also bringing his own magic into it. Maybe they team up to fight against a common enemy.