A plot could involve Harry being cursed by a dark spell that links his fate to Bellatrix and her harem. He initially resists, but then realizes that the only way to break the curse is to understand the motives and emotions of those in the harem. As he delves deeper, he uncovers secrets about Bellatrix's past that explain why she has a harem, and this new - found knowledge helps him find a solution to the curse.
One idea could be that Harry discovers a hidden side of Bellatrix where she has a group of followers who are all intrigued by Harry's power. They form an uneasy alliance at first, but as time goes on, they start to respect and care for each other in their own strange way.
A really interesting plot could be Bellatrix being given a chance at redemption. In this fanfiction, she could start to question Voldemort's motives after seeing the destruction he causes. She might then try to secretly help the Order of the Phoenix. Also, a plot about her teaching a young Death Eater the ways of the Dark Arts and having second thoughts about it mid - way through could be fascinating.
One idea could be a time - travel plot where Harry somehow travels back in time and has to interact with Bellatrix in her younger days. This could lead to him trying to change her path before she becomes a Death Eater.
One idea could be that Bellatrix captures Harry with the intention of using him as a bargaining chip against Dumbledore. She might think that Dumbledore would sacrifice a great deal to save Harry. Another plot could involve Bellatrix trying to turn Harry to the dark side while he's in her captivity, perhaps by showing him 'truths' about the wizarding world that she believes in. Or maybe she captures Harry to extract information about the Order of the Phoenix from him.
Some fanfics explore Bellatrix's family relationships more deeply. Like her relationship with Narcissa. There could be a plot where Bellatrix has to choose between loyalty to Voldemort and protecting her sister, which adds a lot of emotional depth.
Well, it could be that Fem Harry Potter is actually a long - lost relative of Bellatrix's family. Bellatrix initially hates her because of her association with Dumbledore and the Order. But as the story progresses, they find out some dark family secrets that connect them. They then have to decide whether to keep fighting against each other or team up against a greater evil, like a new dark wizard who is more powerful than Voldemort and is threatening the wizarding world.
Well, a cool plot for a 'Harry Potter and Bellatrix Fanfic' might be that Bellatrix, in a moment of confusion during a battle, uses a spell that transports her and Harry to a different time period. There, they have to rely on each other to survive and in the process, Bellatrix starts to question her loyalty to Voldemort. Also, a plot where Bellatrix discovers that Harry has a hidden power that could be used to bring back someone she lost, and she bargains with him for it could be interesting.
Well, perhaps in the fanfiction, Harry and Luna are both involved in a prophecy that brings a group of people around them. These people start to admire and fall in love with them as they witness Harry's courage and Luna's unique wisdom. They all go on a quest to defeat a new dark force, and along the way, the harem - like relationships start to form.
One possible plot idea could be Harry having to balance his relationships with multiple characters from different houses while also dealing with the Dark Lord's threats. For example, he might form a bond with a Gryffindor girl who is brave and adventurous, a Ravenclaw who helps him with his studies and strategic planning against Voldemort, and a Hufflepuff who offers him emotional support during tough times.
One idea could be a story where Bellatrix has a moment of doubt about Voldemort's methods. Maybe she starts to see the destruction he's causing and has to decide whether to stay loyal or turn against him. And Harry Potter could somehow be involved in this internal struggle of hers, perhaps by showing her a different path through his own actions and values.
One idea could be that Harry discovers his true parentage and has to struggle with his identity. He might be torn between the side of good that he has known all his life and the dark legacy of Bellatrix. Another plot could involve him facing discrimination from both the wizarding world that hates Bellatrix and the Death Eaters who might see him as a tool or a threat. For example, he could try to use his knowledge of Bellatrix's magic, which might be more complex and dark - tinged, to fight against Voldemort in a different way than in the original story.