Snape sending Harry a howler in fanfiction can vary greatly. Sometimes it's a turning point for their feud to ease, while in others, it escalates the tension even more. It all depends on the author's imagination and the story's direction.
Harry might be initially shocked and embarrassed. A Howler is a very public form of scolding, and in front of all his friends and classmates, it would be a humiliating experience for him.
Well, it could vary a lot depending on the author's imagination. Sometimes it triggers a series of conflicts and misunderstandings, while in other stories, it might bring them closer together.
It could create a lot of drama and tension. Maybe it leads to a big argument or a revelation of some hidden secret.
The fanfiction usually shows Snape being quite shocked and embarrassed when he gets the howler. It might lead to some interesting character developments and interactions.
Snape might use his skills in potions or dark magic to surprise Lucius. For example, he could quickly brew a potion that temporarily immobilizes Lucius, allowing him to snatch Harry's daughter away to safety.
Hermione could be the sender. If Snape has made some unfair judgment in class against Gryffindor students, Hermione, with her strong sense of justice, might send a howler to him to voice her protest.
He might be initially shocked. After all, getting a Howler is a very public and embarrassing thing. He could be so ashamed that he immediately hides away to read it privately, his face turning red with a mix of anger and humiliation.
In some fanfictions, Snape's cane serves as a symbol of his authority. It can be used to intimidate Harry and the other students, like when he taps it on the floor to get everyone's attention. It represents his strict and often unapproachable nature.
Voldemort might initially be furious. He's not used to being challenged in such a blatant way. He could try to destroy the Howler immediately in a fit of rage.
Snape's reaction could be quite mixed. On one hand, he might be angry at Dumbledore for not doing more if he knew about the abuse. He may also feel a strange sort of empathy towards Harry. After all, Snape himself had a difficult childhood. So, he could start to be a bit more lenient with Harry in his classes and try to subtly offer support.