One plot idea could be that Evangeline Malfoy, being a Malfoy, initially has the typical pure - blood supremacist views. But as she gets to know Harry Potter better, perhaps through a shared project at Hogwarts, she starts to question her family's beliefs. She could secretly help Harry and his friends in their fight against Voldemort, causing a rift within her family.
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.
One idea could be a time - travel plot where Harry Potter accidentally travels back in time and meets Abraxas Malfoy. He could try to change certain events related to the Malfoy family's future actions in the wizarding world. Another plot could involve Abraxas Malfoy leaving behind a mysterious magical artifact that Harry discovers. Harry then has to figure out what it does and if it has any connection to the dark past of the Malfoy family.
One idea could be a time - travel plot where Hermione and Malfoy are sent back in time together and have to rely on each other to get back, while Harry is somehow involved in the events that led to their time - travel. Another could be a story where they are all part of a secret magical project that forces them to work together despite their differences. Malfoy might have some unique knowledge that Hermione respects, and Harry could be the mediator between their clashing personalities.
One idea could be that Harry discovers Narcissa has a secret mission to undermine Voldemort from within. Maybe she's been secretly helping the Order of the Phoenix all along and Harry stumbles upon this knowledge.
One idea could be that Female Draco, being a Slytherin, is initially at odds with Harry but then they are forced to work together on a secret project to save Hogwarts from a new dark threat. This would involve them gradually getting to know each other better and realizing they have more in common than they thought.
One plot idea could be that Abraxas Malfoy, being from an older generation, has some long - forgotten knowledge about Hogwarts' secrets. Harry discovers a diary or an old parchment left by Abraxas that leads him on a quest to find a hidden magical artifact within the school. This could involve Harry having to interact with the ghosts of Hogwarts who knew Abraxas personally.
One idea could be that Harry is sorted into Slytherin instead of Gryffindor. He then has to deal with the prejudices within his own house as well as from other houses. Draco could initially be hostile but then they gradually become friends as they discover they have more in common than they thought, like their ambition and a desire to prove themselves. They could team up to solve a mystery within the Slytherin common room that is linked to the dark history of the house.
One interesting plot twist could be that Harry, now reborn as a Malfoy, uses his knowledge of the future to prevent certain dark events in the wizarding world that the original Malfoys were involved in. He might try to change the family's loyalty from Voldemort to the side of good.
Another plot could involve Harriet getting into trouble and Draco, surprisingly, coming to her rescue. This could be in a situation where she's wrongly accused of something by other Slytherins. Draco defends her because he has secretly started to admire her courage, which is different from the Slytherin values he was brought up with.
One interesting plot idea could be that Harry teaches Scorpius advanced defensive magic. Since Scorpius is a bright young wizard, Harry sees potential in him and decides to pass on some of his own unique skills. Another could be Harry teaching Scorpius about the importance of friendship across house divides, using his own experiences with Ron and Hermione as examples.