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.
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 plot could be them discovering their relation later in life. For example, Hermione might be adopted without knowing her true family ties. Then, through some magical mystery, she finds out she's related to Lucius. It could lead to a lot of inner turmoil for both of them as they come from very different worlds within the wizarding community.
Well, often their interactions start with hostility. Lucius, being a former Death Eater, would view Hermione as a threat to his pure - blood ideology. Hermione, on the other hand, would see Lucius as a symbol of the old, discriminatory ways of the wizarding world. But in some fanfictions, as the story progresses, this hostility can turn into begrudging respect. For instance, if they are both caught in a dangerous situation where they have to rely on each other's skills.
At first, Lucius might be shocked by Hermione's flirting. He's used to a certain type of pure - blooded behavior, and Hermione, as a Muggle - born, is completely different. But as she continues to flirt, he could become intrigued. He might start to see her in a new light, not just as a Mudblood but as an intelligent and alluring witch.
Well, perhaps he uses his influence in the wizarding world. Maybe he has some connections or knowledge that allows him to intervene and get Hermione out of the abusive situation. For example, he could use his status among the pure - blood families to put pressure on the abusers.
In such fanfiction, Hermione could develop her understanding of the dark side of the wizarding world more deeply. Through her interactions with Lucius, she gets to see the inner workings of the dark wizards. This might make her more empathetic towards those who have been corrupted by the dark side, while also strengthening her resolve to fight against it. Her relationships with other characters could also change. She might become more isolated from her friends at first, but then find new allies among unexpected characters.
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.
Well, in some fanfictions, Lucius might use his charm and power. He could be depicted as very persuasive and use his status in the wizarding world to make Hermione see him in a different light. Maybe he offers her opportunities for knowledge or power that she doesn't get with Draco.
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.