Harry Potter himself is very common. After all, he's the main character in the original series and is likely to be at the center of any apocalyptic events in the fanfiction. Hermione Granger is also frequently seen as she's smart and resourceful, which are great traits in an apocalypse. Ron Weasley is another one, as he's Harry's loyal friend and has his own set of skills.
Well, in some 'Harry Potter Apocalypse Fanfiction', a really cool concept is the transformation of Hogwarts. It could become a fortress against the apocalyptic forces. The house rivalries might disappear as everyone focuses on survival. Also, the idea of magical creatures playing a different role, like the centaurs providing strategic advice or the hippogriffs being used for transportation in a more chaotic world.
Maybe Harry Potter has to use his magic to fight against the apocalyptic disasters like hordes of dark creatures or a spreading deadly magic. He could gather his friends and allies from Hogwarts and the wizarding world to try and stop the end of the world.
Well, an apocalypse in Harry Potter fanfiction can change the magic system in multiple ways. Firstly, the availability of magical resources might change. For example, if there are no more potion ingredients growing in the wild, wizards have to find alternatives or create synthetic ones. Secondly, the way magic is taught and learned could be different. There might be a more urgent need for self - taught magic as Hogwarts could be in ruins. And finally, the very nature of some spells could be altered. Dark magic might become more prevalent and the boundaries between dark and light magic could become blurred as everyone is just trying to survive.
Perhaps a group of radical wizards who believe that the apocalypse was a sign that the old ways of the wizarding world were wrong. They want to create a new order, even if it means using cruel and unethical magic. They see the more traditional wizards, like those who were friends with Harry Potter, as enemies who are holding back progress.
The professors at Hogwarts would also have different interactions. Dumbledore, if he were still alive, would be very diplomatic. He might try to understand the Horsemen's motives and see if there was a way to co - exist or send them back peaceably. Snape, on the other hand, would be more guarded. He might initially suspect the Horsemen of being part of some dark plot. The students at Hogwarts would be both scared and curious. Some of the braver ones might try to get closer to the Horsemen to study them, while others would stay far away. Overall, the interactions would be a mix of fear, curiosity, and attempts at understanding and control.
One interesting apocalypse Harry Potter fanfiction could be 'The Darkest Hour in the Apocalypse'. It might show how the wizarding world copes with a global disaster, like a dark magic apocalypse. The characters would have to use their skills in new and extreme ways.
The characters would change in many ways. Harry Potter, who has already faced so much, would become more of a survivalist. He might be more willing to take risks that he wouldn't have before. Hermione would likely turn into a strategic mastermind, thinking several steps ahead to counter the chaos of the apocalypse. Ron, on the other hand, would probably develop a more serious side. No longer could he rely on just his loyalty and friendship; he'd have to be a fighter. Neville, who has shown great courage in the original series, would become a symbol of hope, inspiring others to keep fighting. And the villains, if any are still around, would either try to take advantage of the apocalypse or be forced to side with the heroes in order to survive.
One idea could be that the Forbidden Forest becomes the breeding ground for the zombies. The magical creatures there are either zombified or in a fight for survival. Hogwarts students, led by Harry Potter, have to use both magic and their wits to fend off the undead hordes while also trying to find a cure within the castle's ancient secrets.
Definitely Harry Potter himself. He has faced so many dark and dangerous things already, so he'd be able to handle zombies. Hermione would also be a likely survivor. Her vast knowledge of magic and quick thinking would serve her well. And Neville Longbottom. He has shown great courage and has a deep understanding of Herbology, which could be useful in creating defenses or finding antidotes.