Maybe Charlie is possessive of Hermione because he sees her as a unique and intelligent witch who he fears might be taken advantage of by other wizards. So he takes it upon himself to be very protective and possessive, which could lead to some conflict with Hermione as she values her independence. This could create a story full of tension and relationship - building moments as they navigate their feelings and boundaries.
One possible plotline could be that Charlie becomes possessive after Hermione shows a particular interest in dragon - related studies, which is Charlie's area of expertise. He might start to act possessively towards her to keep her close and ensure she doesn't get influenced by others in that field.
I haven't come across a particular 'Charlie is possessive of Hermione' fanfiction myself. Fanfiction is a vast world with so many different takes on characters and relationships. It could be that this is a more niche idea that an individual writer has explored. You could also look at the works of authors who are known for exploring less common character dynamics in the Harry Potter fanfiction realm. Sometimes they tag their works in a way that makes it easier to find these kinds of unique relationships.
One possible plotline could be that in a dangerous situation in the wizarding world, like a new dark magic threat emerging. Charlie, with his experience handling dangerous magical creatures, uses his skills to keep Hermione safe. Maybe they are in a place full of dark creatures and Charlie's knowledge of their behaviors helps him fend off attacks aimed at Hermione.
If such fanfiction exists, it could potentially explore themes of inter - house relationships as Hermione is from Gryffindor and Charlie is from Gryffindor too. It might also touch on themes of friendship evolving into something more unusual or unexpected.
Maybe it's a post - Hogwarts story where Hermione, in a more grown - up and jaded world, takes up smoking as she faces the challenges of the wizarding world politics or her own personal demons. It could be a way for the author to show her in a more complex and less - than - perfect light, adding a new dimension to her character.
A possible plotline could be Hermione getting captured by Greyback's pack. She then has to use her wits and magic to escape. Maybe she befriends a young werewolf within the pack and uses that connection to her advantage.
One possible plotline could be Hermione getting to know Dolohov in an alternate universe where he has a different side to him. Maybe she discovers some hidden good in him and tries to redeem him.
Maybe it's because Hermione has unique qualities. Her intelligence and strength might attract James, and his possessiveness could stem from a fear of losing someone so special.
One possible plotline could be that Kurenai becomes possessive over Naruto due to seeing his potential. She might take it upon herself to train Naruto more rigorously than others, which could lead to Naruto growing stronger in unique ways. For example, she could teach him some of her genjutsu secrets, and as he masters them, their bond grows stronger, making her even more possessive of his growth and success.
A plotline might involve Hades having a prophecy that Percy is crucial to his future plans. This makes him possessive as he doesn't want Percy to be influenced by other gods. He could start by subtly manipulating events around Percy. For example, causing problems in Percy's relationships so that Percy feels more alone and might turn to Hades for support. Hades might also be possessive because Percy has a unique connection to the Underworld, like being able to travel there easily, and Hades wants to keep that power close to him.
One possible plotline could be Hermione accidentally gets hit by a spell that causes the transformation. Her friends then have to figure out how to reverse it while she has to deal with the new way people perceive her.