One possible reason could be that Snape fails to deliver crucial information. Voldemort is a very demanding and unforgiving master. If Snape doesn't give him accurate details about the Order of the Phoenix's plans, for example, Voldemort would surely be enraged and punish him.
Snape might endure the punishment in stoic silence. He is a complex character and often used to hiding his true emotions. So, he could just grit his teeth and bear it, all the while plotting his revenge or a way to get out of the situation.
In some fanfictions, Snape might punish Ginny for misbehaving in Potions class. For example, she could be given detention for accidentally causing an explosion during a brewing experiment.
Yes, there might be such fanfictions. In the vast world of Hogwarts fanfiction, various scenarios are explored. However, the nature of the 'punishment' can vary greatly from one fanfic to another. It could be related to Draco's misbehavior in the context of Hogwarts' rules, like getting detention or losing house points. Some fanfictions might focus on character development through these interactions between Snape and Draco.
Another reason might be that Harry is suspected of sneaking around in areas where he's not supposed to be. Snape, as a vigilant teacher, may punish Harry to maintain discipline in the school. He may think Harry is up to something related to the ongoing dangerous situations in the wizarding world and wants to keep him in line.
In fanfiction, Snape's relationship with Voldemort is often complex. Snape was a double - agent, so on the surface he seemed to be loyal to Voldemort. But in fact, he was working for Dumbledore. This creates a lot of tension in their relationship in fanfictions. Some fanfictions might explore how Snape managed to deceive Voldemort for so long, and the psychological stress he endured while being in such a precarious position.
In fanfiction, Snape's relationship with Voldemort is full of mystery. Snape was a Death Eater, yet he was also Dumbledore's man. His relationship with Voldemort was based on lies and deception from Snape's side. This makes for great story - telling in fanfiction. Writers can explore how Snape walked the thin line between loyalty to Voldemort (as far as Voldemort knew) and his true mission for Dumbledore.
Yes, there are some fanfictions with such out - of - the - box concepts in the Harry Potter fanfiction community. However, these are not in line with the original story's canon.
In some fanfictions, Snape might be working with Voldemort because he has been blackmailed. Voldemort could have found out some deep, dark secret about Snape and is forcing him to cooperate. This could be related to Snape's past or something he has done that he doesn't want to be made public.
Harry Potter often features prominently. His relationship with Snape is complex in the original series, and in fanfiction involving Snape and Voldemort, his role can be further explored. For example, how he reacts to Snape's interactions with Voldemort and whether he can figure out Snape's true motives sooner.