Well, Draco's character can develop in different ways. If he kidnaps someone for love, like a girl he has a crush on, he might become more vulnerable. He has to show his true feelings instead of hiding behind his Slytherin bravado. He may also become more self - aware as he tries to justify his actions to the kidnapped person. On the other hand, if he's forced to kidnap someone for Voldemort, he might start to rebel against the Dark Lord as he sees the harm he's causing to an innocent person. His character could grow from a pawn in the Dark Lord's game to a more independent thinker.
In some fanfictions, Draco might start to question his family's loyalty to Voldemort. The events of the Goblet of Fire could expose him to the true horrors of the Dark Lord's plans, causing him to develop a more independent and moral stance. For example, he could see the harm that Voldemort's return brings to Hogwarts and its students, and this makes him reevaluate his associations.
In this type of fanfiction, Draco's character could develop in terms of his relationships. The experience of getting spanked could make him more vulnerable, and he may open up to people he previously kept at a distance. He might form closer bonds with those who show him kindness or understanding during this difficult time. It could also make him more introspective, leading to a change in his values and priorities within the wizarding community.
Often, the main characters also include the family members of the kidnapped person. If it's an original character, the writer might create a family for them. Their family could be searching for them, and this could add another layer of drama to the story. Maybe the kidnapped character's sister or brother has some special abilities that they use to try and find their kidnapped sibling.
It could be some of the more radical pure - blood supremacists. They might see Draco as a symbol of the old pure - blood families that are starting to lose their influence. By kidnapping him, they hope to send a message to the Malfoy family and other pure - bloods that they need to be more aggressive in maintaining their status.
A common plot in Draco Malfoy kidnapped fanfiction is that Draco kidnaps a fellow student to get information. He suspects that this student has knowledge about a hidden magical artifact or a secret spell that could help him gain power or status. Maybe he's fallen from grace in the Slytherin house or among the Death Eaters, and he thinks this piece of information will redeem him. Or perhaps he kidnaps someone who he believes has seen something they shouldn't have, like a Slytherin plot against the school, and he wants to keep them quiet.
One interesting plot could be the development of an unexpected friendship between the kidnapped character and Draco. Maybe they start to understand each other's motives and past traumas, leading to a change in their relationship from captor - captive to something more complex.
In many Deathly Hallows fanfictions, Draco starts to question his family's allegiance to Voldemort. This leads to his character developing a sense of independence and moral awakening. He may begin to see the harm that the Dark Lord is causing and try to distance himself from it.
Well, he would probably become more brave and selfless over time. In Gryffindor, the values of courage are highly emphasized. Draco, being in that house, would be constantly surrounded by those who act on their instincts to do what's right. He might start to question his previous Slytherin - like behaviors such as being so focused on pure - blood supremacy. His relationships would also change drastically. Instead of being friends with Crabbe and Goyle, he could form bonds with Gryffindors like Harry, Ron and Hermione, albeit with a lot of initial friction due to their past differences. This new environment would force him to adapt and grow in ways that are completely different from what we saw in the original series where he was a Slytherin.
He could become more empathetic. After seeing the destruction of the war, he might start to understand the feelings of others better. For instance, he may be more sympathetic towards those who lost family members in the war.
His character would likely become more empathetic. Having a baby would force Draco to think about someone other than himself. He'd start to understand the importance of love and sacrifice, which are crucial in raising a child.