There might be some kind of misunderstanding. For example, Ron could have been misinformed about Hermione's actions. He thought she betrayed him in some way, like sharing Gryffindor's secrets with Slytherins, so he lashes out at her.
Perhaps Ron was under the influence of a Dark object or a spell that made him lose control of his emotions and actions. So, without really meaning to, he ends up hurting Hermione.
Another way Severus could save Hermione is by using his knowledge of the Dark Arts in a positive way. If she was hurt by a Dark spell from Ron (in the context of the fanfic), Severus might be able to counteract the spell's effects. He has extensive experience with Dark Arts spells, so he could figure out what spell Ron used and then use a counter - spell to reverse the damage.
Severus might be developed as a more complex and empathetic character. By saving Hermione from Ron, he shows a side of himself that is protective and caring, which is different from his usual cold exterior. This could be a turning point in how the other characters view him.
One possible plot could be that Ron is under the influence of a dark spell that makes him act aggressively towards Hermione. Severus, being observant, notices this and steps in to protect Hermione. He uses his potions knowledge to create an antidote for the spell on Ron.
One common theme is misunderstanding. Often, Ron misinterprets Hermione's actions or words, which leads to him hurting her. For example, he might think she's being too controlling when she's just trying to help.
One reason could be Snape's sense of justice. Despite his often - cold exterior, he may not tolerate Ron's unjust behavior towards Hermione. Another reason might be that he sees something in Hermione that he values, like her intelligence or her thirst for knowledge, and doesn't want it to be extinguished by Ron's actions.
Charlie might be a character who has known Hermione for a long time, maybe through some other connections in the wizarding world. He sees Hermione as someone in need of protection from Ron, whether Ron is acting out of his own accord or is being influenced by external forces. In relation to Ron, he is the one who stands against Ron's actions towards Hermione.
One popular 'ron hurts hermione fanfic' could be 'The Broken Trust'. In this fic, Ron's actions due to jealousy end up hurting Hermione emotionally. It shows a complex side of their relationship where misunderstandings play a big role.
Well, in some versions, Ron might use his quick wit and knowledge of Hogwarts' secret passages to outmaneuver Draco. He could lead Hermione to safety through a passage that Draco doesn't know about.
Well, in fanfiction, anything can happen. Hermione leaving Ron for Severus might be a way for writers to show Severus in a different light. Perhaps they see Severus as someone who has been misunderstood and Hermione, being the intelligent and perceptive character she is, could be the one to recognize his true worth. But it also shakes up the core relationships we knew from the original series, which can make some fans uncomfortable.
Yes, there are quite a few. You can start by looking on popular fanfic websites like Archive of Our Own. Just search for 'Ron saves Hermione' and you'll find a variety of stories with different plotlines and writing styles. Some might focus on a dangerous situation in the wizarding world where Ron heroically rescues Hermione from dark wizards or other threats.