One common theme is justice. Fans often write about characters standing up to Snape to seek fairness, whether it's for themselves or other students. Another theme is courage. It takes a lot of guts to go against a strict and often intimidating teacher like Snape. And friendship also plays a role. Usually, the characters who stand up to Snape are supported by their friends, showing the strength of their bonds.
One popular 'stands up to Severus Snape' fanfiction might be 'The Gryffindor's Rebellion'. In this fic, a brave Gryffindor student decides to confront Snape about his unfair treatment of students. The story delves into the power dynamics within Hogwarts and how students can rise against authority figures. It shows great character development for the protagonist as they overcome their fear of Snape and fight for justice.
One key moment could be in the potions class. Snape might be unfairly criticizing Hermione's potion - making skills, and she just refuses to take it silently and stands up to him, stating her case clearly. Another moment might be when Snape is being overly harsh on one of her friends, and Hermione steps in, protecting her friend and facing Snape's wrath head - on.
One common plotline is that Harry stands up to Snape over unfair treatment of his friends, like Hermione or Ron. Another could be about standing up for the rights of all students against Snape's sometimes harsh disciplinary actions. There might also be a plotline where Harry stands up in defense of his own magical abilities when Snape doubts him.
A great fanfic could be where Hermione stands up for Snape when some other characters are gossiping about his past as a Death Eater. She might argue that people should be judged by their present actions and not be condemned forever for past mistakes. She could point out how Snape has risked his life countless times to protect the students at Hogwarts, like when he tried to keep the Death Eaters at bay during the school's attacks. This shows that Hermione recognizes his true worth and is not afraid to go against the popular opinion to defend him.
In these fanfictions, Harry's character often shows great growth. Standing up to Snape means he's overcoming his fear and asserting himself. It could be a sign of his maturing confidence, no longer being intimidated by Snape's harsh exterior. This also might lead to a different dynamic in their relationship, perhaps towards mutual respect as Snape may start to see Harry in a new light.
A common reason is that he's under extreme stress. In the world of Hogwarts, Snape has to constantly balance his double - agent life. The stress of hiding his true allegiances from Voldemort and the Order of the Phoenix can take a toll on his body. So, it's not unthinkable that this stress could make him physically ill, leading to vomiting. Another reason could be his love for Lily. In some fanfictions, memories of her, especially painful ones like her death, can be so overwhelming that it causes a physical reaction like throwing up.
At first, it would likely strain their relationship even more. Snape is used to having the upper hand and Harry's defiance would anger him. But in the long run, it could lead to a grudging respect from Snape. He might start to see Harry as more than just James Potter's son and realize that Harry has his own strength of character.
One possible scenario could be in a potions class. Snape might be unfairly criticizing Harry's work as usual, but this time Harry decides he's had enough. He stands up, looks Snape in the eye, and calmly but firmly defends his potion - making process, explaining how he followed the instructions correctly. This could shock Snape into silence for a moment.
It often changes the perception of Snape among other characters. When Hermione stands up for him, some characters who previously disliked or distrusted Snape start to question their own views. For example, in a fanfic, after Hermione's defense, Ron might start to see Snape in a new light and be less hostile towards him.