A possible plot in an 'Elsa Kidnapped' fanfiction is that Elsa is kidnapped by a long - lost relative who has a grudge against her family. This relative blames Elsa for something in the past and wants to make her pay. Meanwhile, Elsa tries to use her powers to escape while Anna and the others search for her. They might face many obstacles along the way, like treacherous terrains and false leads. But with determination and love for Elsa, they keep on looking until they find her and bring her back safely to Arendelle.
One plot idea could be that Elsa is kidnapped by an evil sorcerer who wants to use her ice powers for his own dark deeds. The heroes from her world then have to embark on a journey to rescue her. Another could be that Elsa is kidnapped by a group who think her powers are a threat and they plan to keep her locked away forever. However, her sister Anna discovers her whereabouts and tries to free her.
One idea could be that a powerful dark sorcerer kidnaps Elsa because he wants to use her ice powers for his own evil deeds. He locks her in a magically sealed dungeon deep in an ancient castle. Another plot could involve a group of thieves who mistake Elsa for a valuable princess they can ransom. They take her to a hidden lair in the mountains. A third option is that a jealous rival from another kingdom, who envies Elsa's powers and her popularity, arranges the kidnapping to discredit her.
Well, one possible plot could be that Hans has some hidden motives for kidnapping Elsa. Maybe he wants to use her powers for his own gain, like ruling Arendelle through her magic. He could hold her in a secret location and try to force her to cooperate.
One possible plot could be that Jack Frost, perhaps out of loneliness or a misunderstanding, kidnaps Elsa. He takes her to his icy realm. Elsa is initially scared but then realizes Jack has his own insecurities. They start to talk, and Elsa, with her power over ice, shows Jack new ways to use his powers. Eventually, they become friends and Jack realizes his mistake and returns Elsa to Arendelle.
One plot idea could be that Cinderella is kidnapped by an evil sorcerer who wants to use her beauty for a dark spell. Her fairy godmother then has to enlist the help of the animals she befriended to rescue her. Another idea is that Cinderella is kidnapped by a jealous rival from another kingdom who wants to take her place at the prince's side. The prince then sets out on a heroic quest to find and save her. A third plot could involve Cinderella being kidnapped by a group of bandits who mistake her for a wealthy noblewoman, and she has to use her wits to escape.
A possible plot is that Elsa's kingdom is threatened by a force that is related to the same kind of threats the Avengers face. The Avengers hear about her and her powers and travel to her world to offer their help. Along the way, they learn about her backstory, and she learns about their heroics. Together, they combine their powers to save her kingdom and in the process, Elsa decides to join the Avengers on some of their adventures in their own universe.
Maybe the Gerudo see Zelda as a key to unlock an ancient prophecy that they think will benefit them. So they take her. During her captivity, Zelda could try to reason with the Gerudo, learning about their culture and beliefs, and in the end, a mutual understanding could be reached, and she could be released without the need for a violent rescue by Link.
Another plot could be that Rapunzel is kidnapped by a mysterious figure from her past that she doesn't remember. As she's held captive, she starts to have flashbacks of her early childhood and discovers secrets about her family. Meanwhile, Flynn Rider and the others are on a frantic search for her, and Rapunzel has to find a way to signal them while also dealing with the revelations about her past.
One idea could be that a rare and powerful Pokemon is kidnapped by a mysterious organization aiming to use its power for evil. A young trainer then sets out on a dangerous journey to rescue it. Another could be a Pokemon being kidnapped from a Pokemon sanctuary, and the local Pokemon community unites to get it back.
One plot idea could be that a group of dark mages kidnap Erza to use her as a bargaining chip against her guild. They know her strength and reputation, so they think they can force Fairy Tail to give up some valuable magical artifacts. Another could be that an obsessed fan of Erza's kidnaps her, believing that she can be 'tamed' and made to love him. This could lead to a story of Erza having to outwit this deranged individual while also trying to escape from his clutches.
Maybe Mirajane is kidnapped by a dark wizard who has a vendetta against her family. In the fanfiction, the wizard could be trying to force Mirajane to reveal the secrets of her family's magic. Her Fairy Tail comrades would have to figure out where she is and how to defeat this powerful foe.