One possible reason could be a misdirected spell during a battle. In the heat of a fight, Harry's spell could go awry and accidentally kill Malfoy. Another reason might be if Malfoy was under the control of a dark wizard and was about to do something truly terrible, and Harry had to stop him at all costs, including taking his life.
Perhaps Malfoy has crossed a line that Harry can't forgive. Maybe he has betrayed Harry's trust in a way that endangers the entire wizarding world. In a fanfiction, the writer could build up a complex scenario where Malfoy has become so corrupted that Harry, in a moment of desperation, decides that killing him is the only option to save everyone. It could also be that Malfoy has been involved in a plot against Harry's loved ones, and Harry's rage and need to protect them leads to this extreme outcome.
In some 'Harry kills Malfoy' fanfictions, it could be due to a long - standing feud that has spiraled out of control. Malfoy has constantly bullied Harry and his friends, and over time, the hatred has grown so much that a final confrontation ends in Malfoy's death. Or it could be a situation where the wizarding world has descended into chaos, and Malfoy is on the wrong side of the fight, and Harry, as the hero, has to make the difficult decision to kill him to restore order.
Some writers might want to explore the darker side of the character. They could be curious about how Harry would be if he was pushed to his limits and had to kill in self - defense or to protect others in a very extreme situation.
Well, it could be that he has lost all hope. In the fanfiction world, if the situation becomes so dire that he sees no way out for himself or the people he loves. For example, if Voldemort manages to gain complete control and Harry Potter thinks his sacrifice by taking his own life might be the ultimate solution to break Voldemort's power. He might also be suffering from post - traumatic stress after all the battles and losses, leading him to this extreme decision.
In some fanfictions, the power dynamics might be shifted. Maybe Lucius has become more powerful and is on the verge of destroying the wizarding world as Harry knows it. Harry, seeing no other way to stop him, decides to kill Lucius. It could also be a way for the writer to explore the darker side of Harry's character, showing what he could become when pushed to his limits and faced with an unrelenting enemy like Lucius.
Yes, there might be such fanfictions out there. However, in the original 'Harry Potter' series, Harry is not a murderer. Fanfictions that explore this dark concept often deviate from the canon to create alternate, usually more extreme, storylines. Maybe it could be set in a scenario where Malfoy has gone extremely dark and Harry, out of a sense of justice or self - defense, takes such a drastic step. But this is completely against the moral and ethical framework of the original series.
In a 'Harry Potter kills Lucius Malfoy' fanfiction, the motives could be complex. It could start with Lucius's long - standing enmity towards Harry and his family. Harry may have reached a breaking point after all the years of Lucius's attempts to undermine him. Additionally, in the context of the wizarding war, if Lucius is seen as a key figure in Voldemort's regime, Harry might view his death as a strategic move to weaken the Dark Lord's forces. It could also be a way for Harry to assert his own power and dominance over the Malfoy family, who have always looked down on him.
Well, perhaps in a fanfic, Malfoy could be involved in a plot to destroy Hogwarts and Harry, in a fit of rage and desperation to protect his school and friends, ends up killing Malfoy. Or it could be that Malfoy is working with a new, extremely dangerous dark force, and Harry's attempts to stop him go too far and result in Malfoy's death. There could also be a scenario where Malfoy accidentally gets caught in the crossfire of a battle between Harry and another dark entity, and Harry is blamed for his death.
One reason could be that Malfoy fanfiction can humanize Malfoy. In the original story, Malfoy is often seen as a bully. But fanfiction can dig deeper and show his insecurities, dreams, etc. This new view of Malfoy can make Harry see him in a different light and appreciate the complexity of their relationship more, so Harry should thank the fanfiction.
One reason could be revenge. Draco might feel that Harry has wronged him in some way throughout their years at Hogwarts, like getting him in trouble or making him look bad. So, he decides to kidnap Harry as a form of payback. Another reason is that Draco may be under the influence of his family. The Malfoys might see an opportunity to use Harry for their own gain, and Draco is just following their orders.
Some authors might create it as an exercise in 'what - if' scenarios. They want to break the established narrative and see how different characters would react if Harry was killed so early. Also, it could be a way to explore the Dursleys' characters more deeply, showing just how far their hatred for Harry could go.
One reason could be to explore the dark side of human nature. By having Harry kill Ron, the writer might be showing how a good character can be corrupted. Another reason could be to create a shock factor. It's a very unexpected and extreme scenario that can draw readers in.