Their relationship might start with a lot of hostility. Hermione, with her strong sense of justice, would be very wary of Lucius, who has a history of being on the wrong side. But as they interact more, Lucius could be intrigued by Hermione's intelligence and courage. He might start to change his ways to impress her, and Hermione could see the potential for good in him.
One idea could be a plot where Hermione, through some magical accident, is transported to a time when Lucius was young and they meet under different circumstances. Maybe she has to work with him to solve a mystery that could save the wizarding world in that era. This would force them to put aside their initial differences and form an unlikely bond.
One idea could be a story where they are forced to work together on a dangerous mission for the wizarding world. They start off distrusting each other but gradually come to respect one another as mates. Harry's courage, Snape's cunning, and Lucius's ambition could combine in interesting ways to overcome the challenges.
Hermione could be a great addition. She could be the voice of reason when Harry starts getting closer to Lucius. Her intelligence and knowledge of magic could also help in any situation they face together. Another good character would be Draco. Since Lucius is his father, it would add an interesting dynamic. Draco could be conflicted about his father's new relationship with Harry. And of course, Dumbledore. His wisdom and guidance could play a crucial role in how the relationship between Harry and Lucius develops.
For Lucius, his development could be a slow process. At first, he resents being around Hermione, but as he witnesses her magic and her kind heart, he starts to question his own values. He may begin to see the error of his ways regarding blood purity. Hermione might develop more patience. Dealing with Lucius, who has such different views, makes her learn to tolerate and try to change someone rather than just oppose them.
Hermione could also use her magic skills to her advantage. She is a powerful witch, and in the Malfoy household, she may use her magic to create a space for herself where she can be true to herself. She might also use magic to subtly influence Lucius and make him more accepting of her and her beliefs.
One interesting plotline could be the clash of their different ideologies. Hermione, with her strong beliefs in equality and justice, and Lucius, from a traditional pure - blood family with elitist views. Their marriage, forced by the law, might lead to a power struggle within the Malfoy household as Hermione tries to assert her values.
Lucius has a sense of entitlement that comes from his pure - blood upbringing and family wealth. Hermione, being a Muggle - born (in the original story), has had to fight for her place in the wizarding world. So in fanfiction as siblings, Lucius might initially look down on Hermione's more inclusive views, while Hermione would be appalled by Lucius's prejudice. However, as the story progresses, they could learn from each other. Lucius could become more open - minded and Hermione could understand the pressures of a pure - blood family.
In certain fanfiction, Hermione and Harry are soul mates. Writers often take advantage of their shared experiences in the wizarding world. They've been through a great deal together, from facing Voldemort to dealing with the challenges at Hogwarts. This common ground can be seen as the basis for a soul - mate - like bond in these fictional interpretations.
In fanfiction, the relationship between Hermione and Lucius can be quite complex. Some fanfictions might explore a scenario where they are enemies forced to work together due to certain circumstances in the wizarding world. For example, they could be paired in a mission to save Hogwarts from a new dark threat. Their different backgrounds, Hermione being a Muggle - born Gryffindor and Lucius a pure - blood Slytherin, would create a lot of tension and interesting character dynamics.