It could be a rival duelist who is jealous of Marik Bakura's skills and popularity. This rival might think that by kidnapping him, they can steal his secrets and become the top duelist. Another possibility is a group of dark magic users who see Marik Bakura as a powerful source of energy that they can harness for their evil spells.
Well, perhaps a cult that worships an ancient evil entity. They might believe that Marik Bakura has some sort of connection to their deity or is a threat to their plans. So, they kidnap him to either sacrifice him or convert him to their cause. Or it could be a rogue group of thieves who think that Marik Bakura is in possession of a valuable item and they want to ransom him for it.
One likely kidnapper could be a vengeful spirit that has a grudge against Marik Bakura. This spirit might have been wronged in the past by someone related to Marik Bakura and now wants revenge. It uses its spectral powers to kidnap him and hold him in a spectral realm. Another option is a group of power - hungry politicians in the fanfic's fictional world. They see Marik Bakura as a symbol of resistance or a threat to their regime and decide to kidnap him to silence him.
The Joker is a likely kidnapper. He has a history of causing chaos and targeting the Bat - family. He might see kidnapping Batgirl as a way to get back at Batman or just for his own twisted amusement.
Well, in a lot of fanfictions, demons are likely kidnappers. They might want to use Sam for some dark ritual or to get information about the Winchesters' hunting secrets. Demons have always been a big threat to the Winchesters, so it makes sense for them to be the kidnappers.
It could be a group of rogue ninjas. They might see Shikamaru as a valuable asset due to his intelligence and strategic skills. They could plan to sell him to the highest bidder or use him to carry out their own devious schemes.
It could be a rival athlete who is jealous of Serena's success. They might think that by kidnapping her, they can eliminate the competition. Another possibility is a deranged fan who has an unhealthy obsession with Serena and wants to keep her all to themselves.
An evil wizard from a far - off land. He may have heard of Zelda's power and beauty and decides to kidnap her. He could take her to his floating castle in the sky, surrounded by dark magic. Link would then have to find a way to reach the castle and rescue her, perhaps with the help of a magical flying creature.
A secret society that believes Mycroft is a threat to their hidden agendas. They may think that by kidnapping him, they can stop him from interfering with their plans. They would likely be very well - organized and have resources to keep him hidden.
The plot could involve them teaming up to take over the Duel Monsters world. They might use their combined powers and knowledge to outwit other duelists and gain ultimate control.
It could be a vengeful god or goddess. Maybe one who has a grudge against the demigods in general and sees Annabeth as an easy target to send a message. For example, a minor god who feels overlooked and wants to prove their power by kidnapping such a well - known demigod.
Maybe a secret admirer who is too shy to approach her normally. They think that by kidnapping her, they can have some alone time with her and confess their feelings. However, this is a very extreme and wrong way to go about it. Another possibility is a group of thieves who think Haruhi comes from a wealthy family and they can get a big ransom for her.
It could be Discord. He loves chaos and might think it's fun to kidnap Twilight and see how her friends react. He could also be after her knowledge of magic to cause more mischief in Equestria.