Well, perhaps Harry is the heir of Voldemort because of some long - forgotten family connection. In the fanfic, his friends could initially be very skeptical and afraid of him. But as the story progresses, Harry proves that he is not influenced by Voldemort's evil ways. He could discover that being the heir gives him the power to reverse some of the dark magic Voldemort has spread, like a counter - curse to the dark mark. This would make his journey not only about self - discovery but also about saving the wizarding world in a new and unexpected way.
A plot idea might be that the wizarding world initially turns against Harry when they find out he's Voldemort's heir. However, Harry uses this new identity to his advantage by understanding Voldemort's motives better. He could start to study dark magic not to use it for evil, but to find ways to counter it more effectively. For example, he might find a way to use some of the spells Voldemort created to protect the school instead.
In some 'harry potter unknown heir fanfic', the heir might be an outsider in the wizarding world, not from a well - known pure - blood family. This could create a story where they face discrimination and prejudice from some of the traditional wizarding families. But at the same time, their unique perspective and new - found powers help them to make allies among those who believe in equality and change in the wizarding world.
One idea could be exploring how the Heir of Arcturus Black discovers hidden Black family magic. Maybe they find a secret chamber in the Black family home filled with ancient spells and artifacts. Another could be their interaction with Harry Potter. They might team up to fight against the resurgence of dark wizards in Hogwarts.
One idea could be that Harry discovers a new spell that can penetrate Voldemort's dark magic defenses and uses it to shoot him. Another could be that Harry teams up with some unexpected allies, like the house - elves, who help him get in a position to shoot Voldemort. Maybe Harry has to sacrifice something important, like his invisibility cloak, to gain the power needed to fire the shot that will defeat Voldemort.
One interesting plot idea could be that Harry discovers a new and ancient magic that gives him an unexpected edge in the duel. For example, he might find a spell that can temporarily freeze Voldemort's dark magic, allowing Harry to strike. Another could be that Harry has a vision during the duel that shows him the true source of Voldemort's power, and he uses this knowledge to target it directly. Maybe it's a hidden object or a bond with a dark entity that Harry manages to sever, weakening Voldemort.
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.
Maybe Harry absorbs Voldemort and then has to deal with the internal struggle of Voldemort's thoughts within his mind. He constantly battles Voldemort's voice, which tries to persuade him to use power in a wrong way. But Harry uses his own strong will and the love he has for his friends and family to overcome it.
One plot idea could be that the female Voldemort has a change of heart. Maybe she starts to see the error of Voldemort's ways after interacting with Harry Potter. She could start to secretly help Harry and his friends against the Death Eaters, which would create a lot of internal conflict within the Dark side.
Well, perhaps in this fanfic, Harry is raised by Voldemort to be his ultimate weapon against the wizarding world. He's trained to be extremely powerful in combat magic. But as he grows, he starts to notice the fear and suffering Voldemort causes. This could lead to an internal struggle within Harry, between his loyalty to the man who raised him and his own sense of right and wrong. Also, there could be a plot where Harry uses his unique position to secretly undermine Voldemort's plans from within his own ranks.
One plot idea could be Harry growing up in a very different environment. Instead of the Dursleys, he's raised in the dark wizarding world under the influence of Bellatrix and Voldemort. He might struggle with his identity, having the blood of both a hero (in a way, as he's related to Harry Potter in the original story) and two of the darkest wizards. He could be trained in dark magic from a young age but have an inner conflict due to some latent goodness in him.
One idea could be a fanfiction where Voldemort has a change of heart due to some ancient magic. Maybe he discovers a spell that shows him the true consequences of his actions and decides to work with Harry to fix the wizarding world instead of destroying it.