Moony might be protective of Hermione because he has a strong sense of justice. In the wizarding world, Hermione is a Muggle - born, and she often faces discrimination. Moony, being a member of the Order of the Phoenix, is against all forms of prejudice. He would naturally want to protect her from any harm, whether it's from Death Eaters or just general bigotry within the wizarding community. Also, Hermione's intelligence and her role in fighting against the dark forces make her an important asset, and Moony would understand the need to safeguard such a valuable ally.
In some fanfictions, during battles at Hogwarts, Moony is often shown as standing in front of Hermione to shield her from dark spells. For example, when Death Eaters attack the school, he might push her out of the way of a Killing Curse. Another instance could be when Hermione is being bullied by some Slytherins for being a Muggle - born. Moony steps in and scares them away with his werewolf - like presence. He also might accompany Hermione when she has to go to some dangerous places, like the Forbidden Forest at night, to protect her from any lurking creatures or dark wizards.
One common theme is the exploration of an unexpected friendship. Since they are from different generations in the wizarding world, seeing how they bridge that gap is often explored. For example, Hermione's modern - thinking and Moony's more traditional ways.
Moony might start to avoid Tonks while getting closer to Hermione. He could form a study group or some sort of alliance with Hermione, leaving Tonks out. This would create a rift between Tonks and Moony, and a bond between Moony and Hermione.
There's a fanfiction called 'Hermione and Moony: A Forbidden Friendship'. It delves deep into the relationship between them in a world where their friendship is not easily accepted. It shows how they support each other through various challenges in the wizarding world. It's quite engaging as it also brings in other familiar characters from the Harry Potter series to add more depth to the story.
One example could be a story where Moony gets overly protective when other characters show too much interest in Hermione. He might glare at them or subtly insert himself between Hermione and the other person.
In fanfiction, 'claimed' can have various interpretations. 'Moony' might be a character (could be a werewolf reference perhaps, like Remus Lupin's nickname in the 'Harry Potter' series). So, it might imply that in this fanfiction, Moony has a special connection or right over Hermione, like he has declared her as his in some way, be it through a magical bond or a strong emotional attachment within the fictional narrative.
The magical setting of the Harry Potter world is also crucial. It provides a backdrop for their relationship to develop. For example, they might encounter magical creatures or spells together that bring them closer. It gives the writers a lot of scope to create interesting situations for them.
One reason could be that they see her intelligence as an asset. Hermione is known for her brilliant mind, and Slytherins, who value cunning and resourcefulness, might respect that. They could also recognize her strength in the face of adversity and be drawn to protect her as a way to show their own growth beyond the typical Slytherin - Gryffindor rivalry. In some fanfictions, a Slytherin might have a personal connection or debt to Hermione, which leads to their protective nature towards her.
Maybe it's because he admires her intelligence. Hermione is known for her vast knowledge of magic, and Charlie, who has his own area of expertise with dragons, might respect that. He sees her as someone worth protecting because she could contribute a great deal to the wizarding world, and he doesn't want to see that potential lost.