One possible interesting plotline could be Harry's interactions with the Greengrass family. Maybe he forms an unexpected friendship with Daphne Greengrass and through her, gets involved in the complex politics of the pure - blood families in the wizarding world.
It could also be that Harry has a romantic interest in a member of the Greengrass family. This would completely change the dynamics of his relationships in Hogwarts. He might have to deal with the jealousy of other students and the expectations of the Greengrass family while trying to balance his own heroic duties.
Perhaps in this fanfiction, Harry discovers some long - hidden secrets about the Greengrass family that are somehow related to his own past or destiny. This could lead to a series of adventures where he has to rely on the Greengrass family's help to uncover the truth.
Some fanfictions have a plotline where Daphne Greengrass has a secret power or ability. Harry discovers this during their adventures together. Their love grows as they work together to harness or hide this power from the wrong people. It could also lead to a situation where Daphne becomes a target because of her power, and Harry has to protect her, strengthening their bond.
One possible interesting plotline could be how Harry adjusts to his new family. Since the Greengrass family has its own traditions and values, Harry might struggle to fit in at first. For example, he could be unfamiliar with their social circles in the wizarding world. Another plotline could involve how his relationship with the Greengrass sisters develops. Maybe he forms a close bond with one of them and they go on magical adventures together, exploring parts of the wizarding world that were previously unknown to Harry.
One plotline could be that Daphne and Harry team up to uncover a secret society within Hogwarts that is causing trouble. Another is that Daphne, being from a different house, offers Harry a different perspective on the wizarding world and its politics. Maybe she helps him understand the Slytherin way of thinking which aids him in dealing with some of his enemies.
Another plot could involve Daphne Greengrass being a secret admirer of Harry Potter from afar. As the story progresses, she gradually reveals her feelings and they start to bond over their shared experiences of the wizarding world, like dealing with the expectations of their pure - blood families.
A plotline could be where Harry is in a wizarding duel against a powerful and evil opponent. He's outmatched and on the verge of being defeated when Greengrass steps in. She has a special magical artifact that she uses to turn the tide of the duel and rescue Harry. After that, they might embark on a journey together to find out more about the origin of the evil opponent and how to defeat them once and for all.
Another plot could involve Harry's relationship with the Greengrass sisters. He could form a strong bond with them, especially Daphne or Astoria. They might help him in his studies at Hogwarts in a different way compared to his friends in the original story. And as they grow older, their relationships could evolve into something more complex, like a deep friendship or even a romantic interest.
Well, one interesting plot could be Harry learning the unique traditions of the Greengrass family. Maybe he discovers some ancient magic secrets that the Greengrasses have been guarding for generations.
In some fanfictions, Delphine Greengrass could be a key figure in a new prophecy related to Harry Potter. Their destinies become intertwined as they try to figure out the meaning of the prophecy and how to stop an impending doom. This often leads to adventures in places not explored in the original books, like hidden chambers in Hogwarts or forgotten magical lands.
One idea could be that Harry discovers he has a long - lost connection to the Greengrass family. Maybe his mother had a secret friendship with one of the Greengrass ancestors. This could lead to him being involved in some family mysteries within the Greengrass family.
One interesting storyline could be Astoria and Harry's friendship. Maybe they meet in a magical library and start sharing their views on magic and the wizarding world. Astoria might introduce Harry to some ancient spells or magical artifacts that he wasn't aware of before. This could lead to them having adventures together, solving mysteries that are related to Hogwarts' past.