Team Rocket is the most likely candidate. They've always been after Ash's Pikachu and tying him up would be a way to stop him from protecting his Pokémon. They could use ropes or some kind of Pokémon - powered restraining device.
In some Pokémon Ash tied up fanfictions, the situation is more of a misunderstanding. Maybe a group of new trainers thought Ash was a poacher because he was in an area that was restricted for a special Pokémon breeding ground. So they tied him up. Ash then has to explain his situation and his love for Pokémon to them. This type of fanfiction often delves into Ash's character, showing his passion for Pokémon and how he can turn a bad situation into a good one by making new friends among the trainers who initially mistook him.
One possible plot could be that Ash gets tied up by a group of Team Rocket grunts who manage to outwit him. They tie him up to stop him from interfering with their latest evil plan to steal rare Pokémon. His Pokémon then have to work together to free him and foil the villains' scheme.
When Ash is tied up in fanfiction, it usually creates a sense of urgency and danger. It forces other characters, like his Pokémon or his friends, to step up and take action. For example, his Pokémon might have to work together in a different way than usual to rescue him. This can lead to new character developments and relationships.
Most likely not. The 'tied up' concept can easily cross into inappropriate or disturbing territory. In the Pokemon fanfiction world, there are much better and more positive stories about Serena that focus on her character development, her relationships with other characters like Ash and her Pokemon, and her adventures in the Pokemon universe.
I'm not entirely sure as 'ash tied up fanfic' could refer to a very specific piece of fan - created fiction. It might be about a character named Ash who gets tied up in some sort of situation, perhaps in an adventure or a mystery where they are restrained for some plot - related reason.
One interesting Pokemon tied up fanfiction could be about a trainer's Pokemon getting tied up in a tricky situation during a mysterious dungeon exploration. For example, Pikachu might get tied up by some strange vines in an ancient forest while the trainer has to figure out how to free it without causing harm. Another could involve a group of Pokemon being tied up by a villainous team, and their struggle to break free and save the day.
I'm not sure if there is an existing 'pokemon dawn tied up fanfic' available. Fanfics can be quite diverse and often found on various fanfiction platforms, but this specific one might be hard to find or may not exist at all.
For Ash, Pikachu is always a great choice as it's his most loyal and powerful partner. Alongside that, a strong flying type like Charizard could be useful. For Brock, his Onix would be a staple. And perhaps a water - type like Vaporeon could be good for him to balance his team. Since they are teaming up, having a psychic - type like Alakazam could also be beneficial as it can help in battles and also with communication in tricky situations.
One interesting 'Ash tied up' fanfiction could be one where Ash is tied up by some mysterious force in a magical forest and his friends have to rescue him. It might involve elements of mystery and adventure as they search for clues to free him.