Well, the plot could involve Harry Potter accidentally stumbling upon an ancient dark magic that creates zombies while exploring some hidden chambers in Hogwarts. Instead of letting them run amok, he manages to gain control over them using his powerful wizarding skills. He could then use the zombies as a sort of secret weapon against his enemies, but he'd also have to deal with the moral implications of using such undead creatures.
The fanfiction might start with a strange outbreak of zombie - like creatures near Hogsmeade. Harry, being the hero he is, decides to investigate. He soon realizes he can control them using a combination of his Patronus charm and some advanced transfiguration magic. He then uses the zombies to protect the wizarding world from a new, unknown dark threat that neither the Ministry of Magic nor Dumbledore had anticipated.
In such a fanfiction, perhaps Harry could use his magic to either command the zombies for some greater good, like using them to fight against Voldemort's forces. He might discover a new spell that allows him to control their minds. Maybe he first encounters the zombies in the Forbidden Forest and has to quickly figure out how to manage them before they cause chaos in Hogwarts.
Well, it could be that the zombies are magically created in the wizarding world. Maybe Voldemort's followers use dark magic to raise an army of zombies. Harry would use his spells like Expelliarmus to disarm the zombies first. Then he might use the Patronus charm to keep the zombies at bay as the Patronus can act as a powerful shield against dark creatures.
It could be a dark wizard who also wants to control the zombies but for evil purposes. Maybe a long - lost relative of Voldemort who has emerged from the shadows and sees the zombies as a means to finally take over the wizarding world. He might try to steal Harry's method of controlling them or create more powerful zombies that are immune to Harry's control.
Maybe Harry discovers a new spell that allows him to control metal. He could use this power to defend Hogwarts. For example, he might be able to manipulate the metal gates to keep out dark wizards.
Well, perhaps the plot could involve Harry using his newfound powers to bring about major reforms in Hogwarts. He might control the curriculum to include more practical magic for real - world situations.
The plot could involve Harry using his magic in ways that mimic the powers of a God Slayer. For example, he might be able to defeat dark creatures with a new kind of magic that has elements similar to God Slaying powers. Maybe he discovers an ancient magic that is related to the concept of slaying gods and has to use it to save the wizarding world from a new, extremely powerful threat that is almost god - like in nature.
Well, one possible plot could be that Superman somehow gets transported to the wizarding world of Harry Potter. Maybe he's chasing a powerful magical artifact that has been stolen and ends up in Hogwarts. There, he could meet Harry and his friends. They might initially be suspicious of him, but then realize his good intentions when he helps them fight off some dark wizards who are after the same artifact. The combination of Superman's superpowers and the magic of the wizarding world would make for some really exciting battle scenes.
Well, it could be a very dark plot. Maybe Harry is under some dark magic influence that makes him lose his mind and start killing. It would completely change his character from the original story.
If Harry Potter becomes an obscurial in fanfiction, the story could take a very different turn. He might not be as eager to attend Hogwarts as he was originally. The Dursleys might have an even worse time with him because his obscurial powers could lash out. At Hogwarts, teachers would be extremely concerned. Snape, for instance, might be even more critical of him, seeing him as a potential danger. And Harry would have to learn to control this new and dangerous aspect of himself.
In fanfiction, if Harry Potter controls the dead, it could completely change the power dynamics in the wizarding world. It might give him an edge in battles, as he could summon the knowledge and skills of the deceased. For example, he could get strategic advice from great wizards of the past. However, it also raises moral questions. Is it right to use the dead in such a way? It goes against the natural order in the original Potter universe.
One idea could be that the zombies are created by a dark magic spell gone wrong in Hogwarts. Maybe a student accidentally unleashes it during a potions experiment. The students and teachers then have to use both magic and their wits to fight the zombies while also trying to find a cure.