Well, Draco may transform from a bully - like character into a more protective one. He is betrothed to Hermione, so he feels a sense of responsibility towards her. This makes him more likely to stand up for her against other Slytherins or any threats. Hermione's personality could shift in that she becomes more diplomatic. She has to navigate the tricky waters of being betrothed to a Slytherin, so she tries to find common ground between Gryffindor and Slytherin values. She also may start to use her intelligence in a more strategic way to deal with the challenges that come with her new relationship.
In these fanfictions, Draco's arrogance usually takes a backseat. The betrothal forces him to interact with Hermione on a deeper level, and he realizes that there's more to her than just being a 'Mudblood' in his old view. His personality becomes more complex as he tries to balance his Slytherin pride with his new - found feelings for Hermione. Hermione, on the other hand, might become a bit more secretive. She has to deal with her new relationship with Draco while also maintaining her friendships, and she may not be as open with her friends about her true feelings for Draco at first.
Hermione's personality might change in that she would have to be more diplomatic. Instead of always speaking her mind bluntly as she usually does, she'd need to consider Draco's feelings and the situation of their arranged marriage. She could become more patient too. For Draco, he might become more self - reflective. Being married to Hermione, who is so different from him, would force him to look at his own prejudices. He could develop a more humble side as he realizes that Hermione has a lot to offer despite being a Muggle - born.
Hermione's personality might become more open - minded. Initially, she has a very fixed view of Draco as a bully. But with the marriage contract, she has to see him in a different light. She might become more empathetic towards him. For Draco, he could become less arrogant. The forced proximity with Hermione makes him realize that his pure - blood supremacist views are not as valid as he thought. He starts to respect Hermione's Muggle - born status and even learn from her in some ways.
In these fanfictions, Draco often changes from his typically haughty and Slytherin - like self. His feelings for Hermione might make him more open - minded and less prejudiced. Blaise, too, may become more empathetic. For Hermione, she might become more in touch with her emotions rather than just relying on her intellect all the time.
The family members themselves can also play a role in character development. Draco's parents, for example, could start off as cold towards Hermione but then be influenced by her intelligence and kindness. This change in their attitude could then affect Draco and how he views his relationship with Hermione. Similarly, Hermione's family, if included, could show their support for her new connection, which would give Hermione more confidence to explore her relationship with Draco further.
Hermione might become more open - minded. Instead of seeing Draco just as a Slytherin bully, she starts to notice his insecurities and the pressures he's under. For Draco, he could become less arrogant. He realizes that Hermione's intelligence and determination are qualities to admire rather than mock. This change in perception of each other paves the way for the kiss.
Draco might become more humble. After experiencing the horrors of the war and the fall of his family's pure - blood ideology, he realizes the error of his ways. He becomes less arrogant and more open - minded. Hermione, on the other hand, could be more forgiving. She has seen so much death and destruction that she decides to let go of some of her past grudges, including those against Draco.
Draco may develop a sense of humility. Growing up as a pure - blood with a sense of superiority, his relationship with Hermione makes him realize that there is more to a person than their blood status. He might start to see the value in things he previously dismissed, like Muggle - born magic. Hermione's personality could shift in the sense that she becomes more in tune with the subtleties of the wizarding world's social hierarchy. She learns from Draco how to navigate the complex relationships within different Houses and among pure - blood families, while still maintaining her core values of equality and justice.
Hermione's personality might become more forgiving. After the war, she's seen so much death and destruction, and she might realize that even people like Draco can change. So she becomes more open - minded towards him. For Draco, he could become less arrogant. The war has humbled him, and being around Hermione, who doesn't tolerate his old - fashioned pure - blood superiority, forces him to reevaluate himself.
In many of these fanfictions, Hermione becomes more forgiving. After the war, she realizes that people can change, and she applies this to Draco. For example, in some stories, she doesn't hold his past actions against him as much as you might expect. Draco, on the other hand, often becomes more humble. He realizes the error of his ways and is trying to be a better person.
In these fanfictions, Hermione's usually studious and rule - following personality might become more adventurous in the night club setting. She might let her hair down a bit and be more open to new experiences. Draco, on the other hand, who is often seen as cold and haughty, could show a more vulnerable side. Maybe he's not as confident as he seems when faced with Hermione's intelligence and independence at the club. For example, he might start to question his pure - blood beliefs when interacting with her in this new environment.