Perhaps in this fanfiction, Harry didn't have the right items or knowledge at the crucial moment. The Elder Wand might not have recognized him as its true master, or he could have been betrayed by someone he trusted, which led to his death. Also, the magical world could have been in a more chaotic state, with darker magic being more prevalent and overwhelming Harry's defenses.
In some versions of such fanfiction, the prophecy could have been misinterpreted in a way that led to Harry's downfall. Instead of being the chosen one to defeat Voldemort, he might have been set up to fail. Or the magical powers of Voldemort could have been enhanced by some unknown dark magic source, making him invincible against Harry's attacks. And without the support of Hogwarts or his friends in the right way, Harry was unable to survive the final confrontation.
It might be that in that particular fanfiction, the author was exploring different themes such as sacrifice on a grander scale. Harry Potter sacrificing himself to save the entire wizarding world in a more permanent way than in the original story. For example, perhaps the threat in the fanfiction was so great that his death was seen as the only solution to end the chaos and darkness.
Perhaps in the fanfiction, Harry Potter's death occurs because he tries to rewrite a powerful magic spell that goes horribly wrong. He was always known for his bravery and willingness to take risks in the original series, so this could be an extension of that. His death would then be a tragic consequence of his own curiosity and desire to push the boundaries of magic.
One possible scenario could be that Harry is exiled due to false accusations of dark magic. Maybe the Ministry of Magic, fearing his power after the defeat of Voldemort, spreads lies about him being a threat. Another could be that he chooses exile to protect his friends from a new, unknown danger that is targeting him specifically.
One possibility is that the Dursleys, out of their extreme hatred for anything abnormal, actively sought ways to harm Harry. They might have found some dark magic item or spell that they used against him, and without the proper protection or knowledge to counter it, Harry succumbed. In the world of fanfiction, there are many dark and creative ways to make this tragic scenario come to pass. For instance, the Dursleys could have made a deal with some dark forces, trading Harry's life for their own 'normal' life, and those dark forces would use powerful and insidious magic to end Harry's life.
One possible scenario is that Harry discovers the Force during his time at Hogwarts. Maybe there's a hidden chamber or an old artifact that unlocks this power within him. Another scenario could be that he meets a character from a different universe who teaches him about the Force. For example, a rogue Jedi who has somehow ended up in the wizarding world.
One possible scenario could be that Harry discovers a hidden magical passageway in his tiny bedroom at the Dursleys'. It could be a secret portal created by a well - meaning wizard long ago to help any oppressed magical being in the Muggle world. Harry stumbles upon it while looking for a lost sock or something mundane. Another scenario might be that a group of friendly magical creatures, like house - elves, conspire to help him escape. They create distractions around the Dursley house, like making the pots and pans fly around and creating chaos, which allows Harry to slip away unnoticed.
One possible scenario could be that Voldemort punishes Harry Potter by using the Cruciatus Curse on him. In the wizarding world, this is a very cruel form of torture. Another situation might be that Voldemort imprisons Harry in a dark and desolate place, like the dungeons of Malfoy Manor. He could also force Harry to watch as he harms his friends, which would be a psychological form of punishment for Harry, who values his friends highly.
Well, it could also be Harry who is wrongly thought to be cheating on his partner. In the fanfiction, perhaps some false rumors are spread by his enemies. They create a situation where his friends start to doubt him, and his relationship is put under great strain.
In some versions of this fanfiction, Harry could use his power over the weather to create a diversion during a battle. He might summon a thick fog to hide his allies' movements or a strong wind to blow away the dark spells of the enemies. By controlling the weather, he becomes a strategic asset in the fight against the forces of evil.
Well, perhaps in the fanfiction, the Potter family has some allies that help them in rescuing Harry. For example, they might team up with some powerful but little - known magical families. Or it could be that Lily Potter has a special connection to Harry that leads them to his location even when he is hidden away. They could then use a protective spell to keep him safe from further harm.