Perhaps in this 'Boruto goes missing fanfic', Boruto is lured away by a mysterious figure who claims to have information about his future or his father Naruto's past. He follows this figure without thinking, only to find himself in a strange and dangerous place. His disappearance then sets off a chain of events in the village. People start to suspect that there might be a traitor among them who helped Boruto disappear. His teammates, like Sarada and Mitsuki, would then start their own investigation to find him, facing not only external threats but also internal doubts and suspicions within the village.
It could be the Kara organization. They've been shown to be interested in Boruto's Karma mark in the original series, so they might have finally made a move to abduct him in the fanfic.
In the 'Boruto Goes Kidnapped' fanfic, it could be that the kidnappers are after some special power that Boruto has. His father Naruto would be extremely worried and start gathering all the resources in the village to find his son. Meanwhile, Boruto might be trying to escape on his own, using any opportunity he gets.
Well, in this 'Boruto goes to the past fanfiction', Boruto could potentially change some events in the past. Maybe he tries to prevent some of the tragedies that his father and the others had to endure. But he would have to be very careful because any small change could have big consequences for the future. He might also learn some long - lost ninja techniques that were forgotten in his time, and bring them back to the future to make Konoha even stronger.
If Snape goes missing, Hogwarts would be in chaos. His students would be worried and confused. The other teachers would have to take over his classes, but no one could replace his unique teaching style.
In a 'Boruto meets Kurama' fanfic, Boruto might learn about Naruto's past with Kurama. Maybe Kurama would share some of his old battles with Boruto, giving Boruto a new perspective on his father's journey.
In the 'naruto trains boruto fanfic', Naruto might teach Boruto some powerful ninja techniques. For example, he could show Boruto how to master the Rasengan more effectively. Maybe he'd also train Boruto in the art of stealth and how to read an opponent's moves better.
It could be a rogue ninja who wants to use Boruto to get to Naruto. Maybe someone who has a grudge against the Hokage.
In the 'Harry goes to the hospital fanfic', it's possible that Harry is injured during a Quidditch match. He is then rushed to the hospital. There, he could discover a hidden part of the hospital that has some ancient magic stored. He might also have some deep conversations with his friends who come to visit him about their future plans and the current state of the wizarding world.
Well, in a 'Percy Goes to School Fanfic', Percy might face some bully problems at school. Maybe there are some mean kids who pick on him because he's different.
Maybe Naruto will encounter new types of ninjas in the North. He could learn unique jutsu or skills that are specific to that region.