One plot idea could be that Lex Luthor's descendants kidnap Superman's son to use his Kryptonian powers for their evil experiments. They might hold him in a high - tech lair with various traps and defenses. Another could be that an alien race, jealous of Superman's influence on Earth, takes his son to force Superman to leave Earth forever. A third idea is that a powerful sorcerer from another dimension kidnaps the son to use as a bargaining chip to get Superman to retrieve a powerful magical artifact from a dangerous place.
In a fanfiction where Superman's son is kidnapped, the kidnappers could be a group of meta - humans who feel threatened by Superman's family. They might try to brainwash the son to turn him against his father. Or perhaps a time - traveling villain from the future comes back to kidnap the son, aiming to change the future where Superman's descendants become too powerful. Also, it could be a cult that believes the son has some sort of divine power and wants to use him for their rituals.
One idea could be that Ultraman is from a different dimension where he's gone rogue. He sees Superman and Batman as threats to his new world - order. He uses his advanced alien technology to kidnap them. Maybe he wants to study their powers to make himself even more powerful in his own universe.
Brainiac could be the villain in a Superman's son kidnapped fanfiction. Brainiac is known for his thirst for knowledge and power. He might kidnap the son to study his Kryptonian physiology and powers. Zod, another Kryptonian, could also be a culprit. He may have different ideas about how to raise a Kryptonian on Earth and decides to take Superman's son to implement his own vision. Additionally, a new, original villain created specifically for the fanfiction could be the kidnapper, perhaps a mad scientist who wants to create a hybrid using Superman's son's DNA.
Perhaps it's a case of a misunderstanding. Superman might think Batman has done something that endangers Metropolis, like developing a weapon that could potentially harm Kryptonians. He kidnaps Batman to find out the truth and keep the city safe. This could lead to a tense stand - off where Batman has to prove his innocence.
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 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.
One potential plot could be that Superman, in a far - off adventure, ends up in the Naruto world and has a relationship with a character there (maybe a new character created for this fanfic). Naruto is born from this union. As he grows up, he is an outcast in the Naruto world because of his strange powers. He then embarks on a journey to find out more about his father. Along the way, he discovers the DC universe and his place in it. He has to learn how to control his powers, which are a combination of chakra and super - abilities. He also has to deal with the politics of both worlds, as some in the DC world might not trust him because of his Naruto - world origin, and some in the Naruto world might fear his new - found powers. In the end, he uses his unique set of skills to bring the two worlds together and form an alliance against a powerful enemy that threatens both universes.
Maybe there's a plot where a powerful alien force arrives on Earth and starts causing chaos. Superman is having a hard time dealing with it alone as the aliens have some new form of kryptonite - like energy. Catwoman, with her stealth and street - smart skills, discovers a way to neutralize the kryptonite - like effect, and they join forces to save the day.
One plot idea could be that Todoroki is kidnapped by a villain who wants to use his powerful quirk for their own evil plans. His friends then embark on a dangerous rescue mission. Another could be that it was a case of mistaken identity and Todoroki has to figure out how to escape while also dealing with the kidnappers' demands. Or perhaps Todoroki is kidnapped by a group who wants to study his unique genetic makeup related to his quirk.
One plot idea could be that Peter is kidnapped by an unknown group and Michelle sets out to rescue him. She could use her wits and some detective skills she has learned over time. Maybe she teams up with some of Peter's friends from school or work.
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.