A plot could involve time - travel. Harry, for some reason, is sent back in time and meets a younger Narcissa. He gets to know her before she becomes involved with the Dark Arts. They form a bond, and as Harry tries to change the future to prevent some of the tragedies in the wizarding world, their relationship deepens. Eventually, they marry in this altered timeline, and Harry has to deal with the consequences of changing the past and his new relationship with Narcissa.
One possible plot could be that in a world where the war ended differently. Harry, having seen Narcissa's true nature in saving him at the end, starts to interact with her more. They find common ground in their love for Draco and a desire to heal the wizarding world. Their relationship slowly blossoms from there, with Harry helping Narcissa come to terms with a new world order, and Narcissa teaching Harry more about the pure - blood traditions in a non - prejudicial way.
Sure, there are often fanfictions that explore unexpected pairings. In the case of Harry Potter and Narcissa Black, it would be a very different kind of story compared to the original series. It might involve a lot of alternate universe elements, like changing the circumstances of their meeting, or reimagining their personalities in a way that makes such a relationship plausible.
Well, perhaps it could involve Harry Potter breaking away from the traditional wizarding world norms. Maybe he meets a Black family member who is a strong and independent witch. They could bond over their shared experiences of dealing with the dark side in different ways. Their relationship might start with mutual respect and admiration, which then blossoms into love.
One possible plot twist could be that Harry's connection to Narcissa changes his relationship with Draco. Instead of being rivals, they could be reluctant allies, with Draco feeling a sense of family loyalty towards Harry. Another twist might be in how the wizarding world reacts. Some might suspect that Harry is now a part of some dark plot due to his Black family connection. And the magical abilities he inherits from the Black family could be different from what he has as a Potter, leading to new challenges and adventures as he tries to master them.
It could be Sirius Black's younger sister who was not mentioned in the original series but is created for the fanfiction. She might have similar rebellious traits as Sirius but also her own unique charm that attracts Harry.
In the 'Harry Potter marries Blackfire' fanfiction, it could start with Harry being sent on a diplomatic mission to Blackfire's homeland. There, he meets her and is immediately drawn to her strength and intelligence. Blackfire, on the other hand, is initially skeptical of Harry but soon sees his true character. As they work together on some magical problem or task in her land, their relationship grows. Their marriage could then be a symbol of unity between the Hogwarts - associated wizarding world and Blackfire's people. It would also bring about changes in how wizards view different cultures and relationships, as Harry and Blackfire would strive to bridge the gaps between their two worlds.
Perhaps there's a prophecy that involves both of them. They are forced to work together to figure out what it means. Along the way, they discover they have a deep connection, not just because of the prophecy but also because of their shared values of courage and loyalty. This connection eventually leads to marriage.
In the fanfiction, it could start with Harry feeling a strange pull towards an ancient magic site. There he meets Hecate. Hecate is intrigued by Harry's unique magic, which has survived so many dark encounters. They begin to collaborate on magical research, and during this process, their relationship deepens into love. Their marriage unites the Hogwarts magic that Harry grew up with and the primordial magic of Hecate. This causes a stir in the wizarding world as many are both excited and fearful of the new power dynamics that will surely follow.
In this fanfiction, perhaps a dark force is threatening both the wizarding world and the mutant world. Harry Potter and Storm are chosen as representatives of their respective worlds to form an alliance. As they work together to defeat the evil, they develop feelings for each other. Their marriage could then be a symbol of the new - found unity between the two worlds, and they would use their combined powers to protect both their peoples.
One possible plot could be that a magical accident or a powerful spell gone wrong transports Harry Potter to Zatanna's universe. They meet and initially have misunderstandings due to their different magical upbringings. But as they get to know each other, they discover that they share a common goal of protecting the innocent. Their relationship develops as they fight side by side against dark forces that threaten both their worlds, and eventually they fall in love and decide to get married.