In the 'darkrai gets kidnapped fanfiction', perhaps a group of trainers who want to control the power of the Legendary Pokémon Darkrai kidnapped it. They might be planning to force Darkrai to battle other Legendaries. This would create a lot of chaos in the Pokémon world as Darkrai is a very powerful and mysterious Pokémon.
In many of these fanfictions, there could be a rival trainer. This rival might be jealous of the captor for getting Darkrai and try to steal it. Also, there could be a Pokémon professor - type character who gives advice on how to handle Darkrai. For example, they might know some special techniques to keep Darkrai calm while captured.
Well, sometimes the story could be about a young and inexperienced trainer who accidentally captures Darkrai. This sets off a chain of events where the trainer has to learn quickly how to handle such a powerful Pokémon. The trainer might face challenges from other trainers who want to take Darkrai for themselves, and also has to deal with Darkrai's own resistance at first.
Well, if Ash gets Darkrai as a starter, he would have a really powerful Pokémon right from the start. Darkrai is known for its ability to induce nightmares and has strong dark - type moves. Ash could use it to quickly gain an edge in battles against other trainers. Maybe he would face some challenges too, like dealing with people who are afraid of Darkrai because of its spooky reputation.
In many fanfictions where Gil gets kidnapped, it could be for various reasons. Maybe it's by a rival group who wants to use him as a bargaining chip against his friends. For example, in some stories, Uma's crew might be targeted because they are seen as a threat in the Isle of the Lost. Gil, being a part of that crew, gets kidnapped. Writers often use this plot device to create drama and show the loyalty and courage of the other characters as they try to rescue him.
One idea could be that Sam is kidnapped by a group of rogue hunters who think he's gone too far in his use of demon powers. They lock him in an abandoned bunker and try to 'exorcise' the 'demon' out of him, not realizing he's in control. His brother Dean has to race against time to find him, following a series of cryptic clues left by the kidnappers.
Natsu was walking through the forest one day when suddenly a group of dark mages emerged from the shadows. They quickly overpowered him with some sort of magic -binding spell. They dragged him away to an old, creepy lair. His friends back at the guild soon realized he was missing and set out on a search mission. Happy flew around frantically looking for any sign of his friend. Lucy, Gray and Erza teamed up and followed some leads they found in the forest. They were determined to rescue Natsu no matter what it took.
Peter's kidnapping was a carefully planned event. The kidnappers had been observing him for weeks. One day, as he entered a park, they grabbed him. They blindfolded him and took him to a secluded location. Peter was scared but he didn't show it. He started to befriend one of the kidnappers, a young guy who seemed a bit hesitant about the whole thing. Peter told him stories about his life and gradually the kidnapper started to have second thoughts. Eventually, the kidnapper helped Peter escape by distracting the others.
It could be a new character created specifically for the fanfiction. Maybe a young scientist who is working on a project related to the super - soldier serum. Since Bucky has a history with the serum, this would create an interesting dynamic.