One idea could be that Darcy, being an Avengers fan, always wears a hair tie on her wrist as a sort of good - luck charm. In the fanfiction, she could be an intern at Stark Industries and one day, while wearing that hair tie, she accidentally stumbles upon a secret project of the Avengers. Maybe it's a new type of weapon or a device that could potentially change the fate of the world. This discovery then thrusts her into the middle of an Avengers - related adventure where she has to use her wits and the 'lucky' hair tie (which could end up having some hidden significance) to help the Avengers save the day.
Well, it could be a simple fashion statement. Maybe Darcy just likes to have a hair tie handy in case she needs to quickly put her hair up, like if she's in the middle of some Avengers - related chaos and doesn't want her hair in her face. It could also be a gift from someone, perhaps a fellow Avenger or a friend, which would add a bit of sentiment to it.
It could be a symbol of a prophecy. In the fanfiction world, there could be an ancient prophecy that mentions a 'band of power on the wrist of a true believer'. Darcy, being an Avengers fan, is the true believer. When the Avengers face a seemingly unbeatable enemy, they start to notice that Darcy's hair tie on her wrist has some strange powers. It glows when danger is near or gives off a force field. This makes the hair tie a central plot device as they figure out how to use its powers to defeat the enemy.
It might not seem like much, but the hair tie could be a conversation starter. Maybe one of the Avengers comments on it, and it leads to a more in - depth conversation, strengthening their bond. For example, Thor could be curious about this strange 'band' on her wrist, and Darcy's explanation could make him see her in a new light.
One idea could be that the hair tie on Misty's wrist is a memento from a special event. Maybe it was given to her by a friend she made during one of her travels in the Pokemon world. This hair tie could hold some sort of power or just be a symbol of friendship that she cherishes. In the fanfiction, she could be in a tough situation where she looks at the hair tie for strength.
It could be a symbol of a particular phase in their life. Maybe when they were younger and more carefree, and now at 40, it represents a connection to that lost youth.
In fanfiction, a black hair tie on the wrist could symbolize a connection to a particular character. Maybe it was given by a love interest, and the character wears it as a reminder of that person. It could also be a sign of a secret society or group within the fanfiction world, where the black hair tie is a form of identification.
One idea could be that the hair tie is a memento from a special moment. For example, in a fanfic, it could be the hair tie that Rory gave to Jess when they were studying together one day, and Jess keeps it on his wrist as a reminder of their connection. It could also be used as a symbol of a secret pact between two characters. Maybe Lane and Rory make a pact to always be there for each other and use the hair tie as a physical reminder, and in the fanfiction, it becomes a crucial part of their friendship story.
The fact that her hair is in a bun might also play a role. It could be a cultural or traditional style in the fictional world she belongs to. When she's kidnapped, her captors might be disrespectful of this style, which angers her and gives her the motivation to resist. The bun could also be used practically during her captivity. For example, she might hide small objects in it to help her escape, like a lock pick or a small note.
Such a description might be used to make the character stand out in a fanfiction. He could be a unique character in a fantasy - based fanfic too. For example, he could be a wizard who has adapted to some modern - day human habits like wearing a hair tie on his wrist. His bun could be a way to keep his long hair out of his face while he's performing magic.
A disgruntled ex - friend could be the kidnapper. Maybe there was a falling - out between the two characters, and the ex - friend wants to get back at the owner of the hair tie. They think that by taking this precious item, they can cause emotional pain.