Well, often in 'Harry Kidnapped' fanfiction, the plot could revolve around Harry being kidnapped for his prophetic powers. If the story is set during the time when he was still a student at Hogwarts, it might involve his friends trying to rescue him. There could be a lot of mystery and danger involved, like the kidnappers leaving cryptic clues or having some sort of elaborate plan to use Harry's magic for their own evil purposes. Also, some stories might explore how Harry copes with being kidnapped, whether he tries to escape on his own or waits for help, and how this experience changes him as a character.
One common plotline could be the characters' efforts to rescue the kidnapped person. For example, Carly and her friends might use their wits and resources to track down the kidnapper. Another could be the emotional turmoil of the victim and their friends during the ordeal. The fanfiction might also explore how the iCarly crew deals with the media attention that comes with such a serious situation.
One possible plotline could be that the kidnappers are actually working for a powerful dark wizard who wants to raise Harry to be his minion. Another could be that the kidnappers take Harry to a far - off land where he grows up without knowledge of the wizarding world until he discovers his true identity in a very unexpected way.
A common plotline is that a main character like Kagome is kidnapped by a powerful demon and Inuyasha is the only one who can save her. He has to use his strength and the power of his sword. Another is when Inuyasha accidentally kidnaps someone due to a spell or misinformation.
Often, there's a plotline where Leo's kidnapping is part of a bigger scheme against the turtles. For example, the kidnappers might be working for a more powerful enemy who wants to take over the city. Another common plotline is Leo being kidnapped to be used as a bargaining chip, like to get some sort of valuable item from his brothers.
A common plotline could be that Rachel is kidnapped for ransom. Her family or the glee club is demanded to pay a large sum of money for her release. Another is that she is kidnapped by a deranged fan who is obsessed with her singing. This fan might want her to sing only for them.
Sometimes, the fanfiction might involve a mystery aspect. Why was Webby kidnapped? It could be related to some hidden treasure or a power that she unknowingly has. Unraveling this mystery becomes a big part of the story as the characters try to find and save her.
Sometimes, Jack is kidnapped by supernatural beings. These could be ghosts or ancient sea creatures. They have their own motives, like using Jack as a sacrifice or a key to unlock some ancient power. Jack then has to use his knowledge of the supernatural world, which he has gained from his many adventures, to free himself.
A common plotline is the rescue mission. Her friends and family band together to find Betty. Another is the discovery of the kidnapper's identity. It might be someone from her past or a new enemy in town.
A common plotline is the rescue mission. His friends from Fairy Tail band together to find and save him. Another is Natsu trying to break free on his own. He might use his fire magic in creative ways to escape his bonds.
One common plotline could be that Twilight's friends set out on a grand adventure to rescue her. They might face various obstacles and villains along the way. For example, they could encounter a powerful dark magic user who has kidnapped Twilight for her knowledge of magic. Another plotline might involve Twilight using her own wits and magic, even while kidnapped, to try and escape or send messages to her friends. It could also be that the kidnapper has some sort of vendetta against Twilight because of her status in Equestria and plans to use her as a bargaining chip.