Well, in this kind of fanfic, Harry could be neglected by Hogwarts staff. For example, teachers may be too preoccupied with other matters, such as political unrest in the wizarding world. Harry, feeling alone and abandoned, might venture into dangerous areas like the Forbidden Forest more often. He could encounter a powerful and malevolent creature that he's not ready to face, and ultimately die because there was no one to rescue him. Also, the Sorting Hat could potentially mis - sort him into a house where he doesn't fit in at all, and the neglect from his housemates could contribute to his downfall.
The wizarding world would be in chaos. They would realize too late that they had pinned all their hopes on Harry and neglected him. There would be a great sense of guilt and despair. The Hogwarts students would be shocked and many would feel a deep sense of loss. The teachers might question their own actions and inactions that led to this. The Order of the Phoenix would be in disarray, having lost their main weapon against Voldemort.
One possible plot development could be that Harry discovers his magic earlier on his own due to the neglect. He might start exploring the wizarding world secretly, finding hidden magical artifacts in the neighborhood. Another could be that he forms an unexpected alliance with the local magical creatures that sense his isolation. Maybe he even starts teaching himself basic spells from an old, dusty spellbook he finds in the attic.
One possibility could be that Voldemort manages to find and kill Harry much earlier. Maybe the protection spell that Lily cast fails due to some unforeseen dark magic interference. This would change the entire wizarding world. Hogwarts might be taken over by Death Eaters completely, and there would be no 'Boy Who Lived' to inspire hope. The Order of the Phoenix would likely be crushed much sooner, and the wizarding world would descend into a much darker and more oppressive state than in the original story.
If Harry dies instead of Cedric in fanfic, Hogwarts would be in a state of deep mourning. The entire wizarding world that had placed so much hope in Harry would be in shock. Voldemort would likely face less opposition in the short term as Harry was seen as the main threat to his return. Friends like Ron and Hermione would be devastated, and they might have to take different paths. Ron could become more withdrawn, and Hermione might focus all her energy on finding a way to avenge Harry. The story would also likely shift focus to Cedric, who would now carry the weight of the prophecy or the task of ultimately facing Voldemort, if there was such a concept in this altered universe.
You can start by looking on fanfiction websites like Archive of Our Own or FanFiction.net. Use the search bar and type in relevant keywords like 'neglected aspects of Harry Potter' or 'minor characters in Harry Potter fanfic'. Then browse through the results to find ones that seem interesting.
Well, there are indeed. The concept of Harry being neglected by his parents in fanfics gives a whole new perspective. It allows the author to explore how Harry's prodigious abilities might manifest in a more desperate situation. He might be more resourceful and independent, which is a fresh take on the Harry Potter character. Some fanfics also show how this affects his relationships with other characters in Hogwarts.
In many of these fanfics, there could be a new character introduced, like an old wizard who lives in the neighborhood secretly and notices Harry's situation. This character might play a crucial role in helping Harry deal with the Dursleys and his growing magical powers. He could be a mentor figure for Harry, guiding him through the tough times.
One possibility could be that in a magical world where Harry Potter exists, Batman's skills and detective abilities are overlooked. Maybe Batman is magically transported to the wizarding world and is initially dismissed as just a Muggle with no real value. But he starts using his gadgets and his sharp mind to solve mysteries that even the wizards can't figure out, like a series of strange disappearances in Hogwarts that are related to some dark magic - Muggle technology combination.
One possible plot could be that in a magical world where both Harry Potter and Pokemon exist, Harry discovers a hidden Pokemon reserve in the Forbidden Forest. He befriends a neglected Pokemon there, like a Pikachu that was left behind by an irresponsible trainer. Harry decides to take care of it, using his magic to help it grow stronger. Along the way, they face challenges from both the wizarding world, who are suspicious of this new creature, and from other Pokemon who see the Pikachu as an outsider in their world.
It may also divide the fandom a bit. Some fans who are more attached to the original positive and heroic narrative of Harry may not like the idea of him dying in fanfic at all. While others, who enjoy exploring darker and more alternative storylines, might embrace these 'harry potter dies fanfic' and even contribute to creating more similar stories, which can cause some friction between different groups of fans.