It would be very difficult. However, if the writer were to explore some sort of dark magic corruption on Harry. For example, if he was somehow influenced by a powerful dark object or spell that made him lose his sense of self and morality. But still, it would be a huge stretch from the original concept of Harry's character.
In the original 'Harry Potter' series, the relationship between Harry and Snape was one of mutual dislike but also a certain level of respect in the end. However, in this fanfiction, it's a complete break. The fanfiction might change the power dynamics at Hogwarts as well. Snape was a key figure in the school's hierarchy, and his death at Harry's hands would send shockwaves through the staff and students, unlike anything in the original story where his death was a heroic sacrifice.
One possible motive could be a misunderstanding. Maybe Snape is framed for something really bad, like a dark magic plot against Hogwarts. Harry, in his haste to protect the school and his friends, believes Snape is guilty and takes drastic action. Another reason could be if Snape accidentally endangers someone Harry loves dearly, like Ginny or Ron, and Harry's emotions get the better of him in the heat of the moment.
One common theme could be the exploration of power and corruption. Harry might be depicted as being corrupted by power, which leads him to kill Dumbledore. Another theme could be betrayal. It shows a complete break from the loyalty that was so central to the original story. And there could also be a theme of misinformation, where Harry acts based on false information.
Well, Harry might outsmart Dumbledore by using his unique understanding of the magical world in ways Dumbledore doesn't expect. For example, Harry has a more direct experience with some dark magic items due to his encounters with Voldemort. He could use this knowledge to make decisions that seem counter - intuitive to Dumbledore but are actually more effective in a particular situation.
Perhaps it's his powerful intuition or a charm he has placed that detects such disruptions. Dumbledore is known for his wisdom and magical prowess, so it could be a combination of these factors that allow him to sense the disturbance on Fanfiction.net.
Well, it completely flips the story on its head. Dumbledore is a central and positive figure in the original. His death is a major turning point, but for Draco to kill him for Hermione means Draco's character has a huge shift. It also makes Hermione a much more central and controversial figure, as her presence has now caused such a drastic event. The relationships between the main characters like Harry, Ron and Hermione would be severely strained as they deal with this new and unexpected development.
In the fanfiction, Snape could protect Harry from Dumbledore by using his skills in potions. For example, he might create a potion that hides Harry's magical signature from Dumbledore's detection. Or he could use his knowledge of the Dark Arts to counter any spells or charms that Dumbledore might use to keep tabs on Harry. Snape is very intelligent and resourceful, so he could find various ways to physically and magically shield Harry from Dumbledore.
It completely goes against the character of Harry Potter in the original story. In the original, he is a hero who stands for good and protects his friends and the wizarding world. But in this fanfiction, he becomes a mass murderer, which is a huge subversion.
In some fanfictions, Draco could be under the influence of a dark magic artifact that warped his mind. This could lead him to believe that killing Dumbledore was the right thing to do. He might see Dumbledore as an obstacle to a new order that he's been convinced is better for the wizarding world.
In many such fanfictions, Dumbledore might comfort Snape by reminding him of his good deeds. For example, he could say that Snape's role as a double agent is crucial for the greater good. Dumbledore might also offer a sympathetic ear, listening to Snape's inner turmoil about his past actions and his love for Lily. By validating Snape's feelings and his importance in the fight against Voldemort, Dumbledore provides comfort.