Snape might be initially shocked, but then his face would harden into his typical stoic expression. He'd probably carry Hermione to the hospital wing himself, barking orders at students to get out of the way. Once there, he'd stay until he was sure she was in good hands, perhaps because he secretly respects Hermione's intelligence and doesn't want to see such a bright student in danger.
He might immediately go into a protective mode. He could use his potions knowledge to quickly make a healing draught for her. After all, Snape is very skilled in potions, and Hermione being hurt would likely trigger his instinct to help.
He may show a rare moment of kindness. Given his own past traumas and experiences, he might empathize with Hermione on some level. He could offer her some words of wisdom or even some form of magical assistance to help her get better.
He might be initially startled. Snape is used to seeing Hermione as a strong - willed and confident student. So seeing her crying could catch him off - guard. But then he might quickly put on his usual cold facade and ask her curtly what's wrong.
Snape might be suspicious at first. He might think it's some sort of trick or part of a bigger plot. However, as he observes Hermione more closely and realizes the genuineness of her situation, his attitude could gradually change to one of reluctant assistance. He might even offer some words of wisdom, albeit in his typical sarcastic way, to help Hermione regain her strength.
He might initially show annoyance. After all, Hermione is often seen as a know - it - all in his eyes. But his sense of justice and his underlying good nature (despite his cold exterior) would kick in. He'd untie her in a rather brusque manner, but then start to question her about how she got into this mess. Depending on her answer, he might offer some cryptic advice on how to avoid similar situations in the future.
He would probably be in shock. Snape has spent so much time around Harry in one way or another throughout his years at Hogwarts. His immediate reaction could be disbelief. He might stand there frozen for a moment, unable to process what he's seeing. Then, the full weight of the situation would hit him, and he could break down in a rare display of raw emotion.
He might be initially shocked. Snape has deep and complex feelings for Lily. His reaction could range from a moment of stunned silence as he processes the news. He may also feel a pang of jealousy towards the father, whoever that is. Given his love for Lily, he'd probably be very protective in his own way, despite the situation being complicated by their past and his past actions and associations.
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.
Well, Snape has always had a complex relationship with Harry. When he finds Harry cutting himself in this fanfiction, he might be angry at first, thinking it's a sign of weakness. But then, as he realizes the depth of Harry's pain, he could soften. He might start to see Harry more as a troubled child rather than just James Potter's son. Snape could use his knowledge of potions to create something to heal the physical wounds and also try to offer some form of emotional support, albeit in his own gruff way.
Snape's reaction could be multi - faceted. He might be angry at those who are abusing Draco, but also a bit conflicted because of Draco's family's ties to the Dark side. He could use his position as a teacher to give Draco some extra guidance and support, perhaps in the form of private tutoring sessions where he can also check on Draco's well - being more closely. He may also start to question his own views on the Malfoy family in general.
Sodapop would also be angry. Angry at whoever or whatever caused Ponyboy to be hurt. If it was another person, he'd be ready to confront them. His love for Ponyboy makes him very protective, and this would show in his emotional response.