One possible plot is that Percy was betrayed by someone he trusted deeply in the wizarding community. At Hogwarts, he discovers that there are ancient spells and prophecies that are related to his situation. He starts to study them intently. Along the way, he befriends some outcast students who have their own stories of betrayal. Together, they form a sort of support group. Percy also gets involved in the Hogwarts politics, trying to make changes that would prevent others from experiencing the same kind of betrayal he did. He may even find a way to expose the person who betrayed him using the resources and connections he builds at Hogwarts.
In such a fanfiction, perhaps Percy was betrayed by his family or friends in the Ministry. When he goes to Hogwarts, he might find solace in the old castle. He could reconnect with his siblings in a more understanding way, and learn new magic that helps him in his quest for revenge or self - discovery. He may also team up with some unexpected allies among the students and teachers.
Well, if Percy is betrayed, it could be that he was set up at work. Going to Hogwarts gives him a chance to start anew. He might explore the hidden secrets of Hogwarts, things that were overlooked in his previous school years. There, he could meet a wise old professor who guides him to see the truth about his betrayal and helps him grow stronger in magic. He may also use his knowledge of the Ministry to make Hogwarts a safer place from outside threats.
His own family could have betrayed him in a sense. For example, if they put too much pressure on him to conform to their expectations and he felt suffocated. Feeling betrayed by their lack of understanding, he goes to Hogwarts to find a new sense of purpose and freedom away from the family drama.
He could introduce some new combat styles to the Dueling Club. His experience in fighting monsters as a demigod would give him an edge. He might be a bit of an enigma to the Hogwarts professors too. They would be intrigued by his different kind of magic. And with his being betrayed, he could be a bit guarded at first, but gradually open up as he realizes that not everyone at Hogwarts is like those who betrayed him. He could also discover some hidden chambers or secrets in Hogwarts that have a connection to his demigod world, like a hidden place that has a link to the Greek gods.
Well, it could be that Percy has a hard time adjusting to the wizarding world at first. But then he meets a mentor figure who helps him understand his place in Hogwarts and he starts to thrive. He might even join the Quidditch team and become a star player.
Some students might be in awe of him. His demigod status and the stories he could tell about fighting monsters would be really cool to them. Others might be a bit jealous, especially those who pride themselves on being pure - blood wizards and think their magic is superior. But then there would be those who would be friendly and curious, like the Weasley twins. They would probably want to team up with him to pull some epic pranks using his unique skills.
In the 'Percy goes to Hogwarts alone fanfiction', it's possible that Percy will discover new aspects of himself. Since he's alone, he has to rely solely on his own wits and skills. He could stumble upon some hidden secrets of Hogwarts that others haven't found. Also, he may have some unique encounters with the Hogwarts professors who take notice of his solitary situation and offer him special guidance or tasks.
The plot might involve Naruto making friends with some of the Hogwarts students. He could show them his unique fighting style, like the Rasengan, and they in turn could teach him some basic spells. For example, Hermione could be intrigued by Naruto's chakra system and Naruto could be amazed by her knowledge of magic. There could also be a conflict where Naruto has to face some dark wizards using his ninja abilities, while also learning how to use magic in a pinch.
In the 'sakura goes to hogwarts fanfiction', it could be that Sakura is a transfer student. She would face the challenges of adapting to the different magical system in Hogwarts. For example, she has to learn about potions and spells in the Hogwarts way. Along the way, she might discover a hidden mystery in Hogwarts that only she, with her special background, can solve. Maybe it has something to do with an ancient artifact that links her world to Hogwarts.
Well, it could be about Mal, who might be a new student at Hogwarts. Maybe Mal discovers a hidden magic ability that no one else has. He could make new friends and together they face some sort of mystery in the castle, like a secret room that holds an ancient magic that's in danger of being misused.
Well, it could be about Naruto arriving at Hogwarts and forming a special bond with a male character there. Maybe he meets someone like Draco Malfoy, and they start off as rivals but then develop a deeper, more romantic relationship as they face challenges together at Hogwarts, like dealing with dark magic threats or school rivalries.
Well, perhaps Edward could use his alchemy skills in the magical world of Hogwarts. He might be sorted into Gryffindor for his courage. He could start to learn magic along with the Hogwarts curriculum and have some interesting interactions with the students like Harry, Hermione and Ron. Maybe he'd show them some unique alchemy tricks and in turn learn some new spells.