One way her storyline could develop is if she is sent on a mission by her family, but during that mission, she meets Harry and his friends. They show her kindness and a different way of life. This causes her to have a moral dilemma. She could either go back to her family or side with Harry. If she sides with Harry, she would have to face the consequences from her family, which could be a very dramatic part of the fanfic.
Well, Eva Malfoy could be an interesting addition to a Harry Potter fanfic. If she's related to the Malfoy family, she might have some of the typical Malfoy traits like pride and a sense of superiority. However, in a fanfic, she could also break the mold. Maybe she befriends Harry Potter against her family's wishes, which would create a lot of internal conflict within the Malfoy family and also make for an exciting plotline as she tries to balance her loyalty to her family and her newfound friendship with Harry.
Their relationship could start with mutual suspicion. Harry is wary of Evangeline because she's a Malfoy, and Evangeline is hesitant about Harry due to his reputation as the 'Chosen One'. But as they are forced to work together on a school assignment, they start to see each other's true natures. They gradually become friends and confidants, sharing their fears and hopes.
Bella might start as a typical Malfoy, proud and a bit haughty. But as she interacts with Harry, she could start to see the world from a different perspective. For instance, she may notice how Harry values friendship and loyalty over blood status. This could make her more empathetic towards others outside of the pure - blood circle.
At first, they are enemies. Malfoy hates Harry because Harry is famous and Malfoy wants to be the top wizard at Hogwarts.
It could start with a truce. Maybe during one of their encounters at Hogwarts, instead of fighting, they have a moment of understanding. From there, they might start to notice things about each other that they never did before, like Draco's hidden kindness or Harry's determination in a different light. Then small acts of kindness could lead to deeper conversations and eventually, feelings of love.
Perhaps she is a seeker of some sort of ancient artifact that has significance in both the Bleach and Harry Potter lore. This could lead her to interact with different houses at Hogwarts, each with their own motives regarding the artifact. Some might want to use it for power, while others want to keep it safe. Her journey would involve not only finding the artifact but also dealing with the politics and rivalries within the wizarding school.
His magical abilities might develop in a different way. The Malfoys could introduce him to different types of magic or magical artifacts. Maybe he'd learn more about the Dark Arts in a different context, not for evil purposes but just to understand it better. He could also become more skilled in areas like Occlumency earlier on, since the Malfoys might see it as an important skill to protect their family secrets. His relationship with his Gryffindor traits would be tested. He might still have his bravery, but it could be expressed in different ways, like standing up to the Malfoy family's wrongdoings.
She could make the Malfoy family seem more complex. Instead of just being the 'bad guys', with Isabella there could be some internal family debates about right and wrong.
The story could also focus on their relationship as twins. Despite growing up in different worlds, they might have a deep, instinctual connection. They could start to learn about each other's cultures and worlds. Fem Harry could introduce Sephiroth to things like Hogwarts and Quidditch, while Sephiroth could show her his world's advanced technology or unique combat styles.
In some fanfictions, it could develop due to a common enemy. Maybe there's a new dark force emerging in Hogwarts, and they both realize that they need to put aside their differences to face it. This shared goal makes them rely on each other more, and feelings start to grow as they see the other's courage and determination. Their relationship could grow from a begrudging alliance to a full - fledged romance as they discover new sides of each other.