There's a fanfic called 'Lucius Malfoy's Pain'. Here, he gets hurt during a fight against a powerful dark wizard who turns out to be stronger than him. This not only injures him but also makes him question his own power and status in the dark arts world.
Another theme is family betrayal. Lucius values his family name and status. When his family turns against him or is put in danger because of his actions, it hurts him deeply. In a certain fanfic, his son Draco's disobedience and siding with the good guys is a huge blow to Lucius.
One common theme is family loyalty. In a lot of fanfictions, we see Draco and Lucius sticking together through thick and thin, no matter what the situation is in the wizarding world.
One reason could be for the greater good of the wizarding world. If Lucius is healed, he might be able to turn away from the Dark side and provide useful information about Voldemort's remaining followers.
Many 'Harry Potter Lucius Malfoy Mpreg Fanfiction' stories also explore his relationships in a new light. His relationship with his family, especially Narcissa, could be strained or strengthened. And his relationship with other Death Eaters or Hogwarts faculty might change as they react to his unexpected condition.
Well, in some fanfictions, Harry might use his advanced magic skills he learned from Dumbledore's old books. Maybe he discovers a long - forgotten spell that can reverse the dark magic effects on Lucius.
In fanfiction, it might be due to a redemption arc for Lucius. He realizes the error of his ways in the wizarding war and starts to view Hermione, a muggle - born with great talent, as someone worthy of protection. He could also be protecting her from other dark wizards who might want to harm her because of her intelligence and influence among the light - sided wizards. This protection could also be a form of self - atonement for his past misdeeds against the muggle - borns.
One great Lucius Malfoy and OC fanfiction is 'The Malfoy Heir'. It has a really interesting plot where the OC is a powerful witch who gets intertwined with Lucius's family secrets. Another one is 'In the Shadows of Malfoy Manor' which delves deep into the relationship between Lucius and the OC against the backdrop of the wizarding world's politics.
One possible reason could be the contrast between them. Lucius is from an old, pure - blood wizarding family with dark tendencies, while Hermione is a Muggle - born with strong moral values. This contrast creates an interesting dynamic that fanfiction writers like to explore.
Lucius would probably be quite haughty at first. He's used to being in a position of power in the wizarding world. Bella, on the other hand, would be a bit defiant. But over time, Lucius might start to respect Bella's tenacity.