After Snape discovers the abuse, the relationship undergoes a major transformation. Snape begins to protect Harry from not only the Dursleys but also from any potential threats at Hogwarts. Harry, who has been starved for positive adult attention, starts to trust Snape. Snape, in his own brooding and complex way, starts to care for Harry's well - being. He might even start to teach Harry some advanced magic that he wouldn't have taught him before, seeing Harry's need for strength and self - defense in the context of his abusive home life. This new relationship dynamic is a far cry from their initial animosity.
Harry might start to receive more protection at Hogwarts. Snape could put in place some measures to keep him safe from further harm. For example, he might assign some students to keep an eye on Harry when he's in vulnerable situations.
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.
In the fanfic, Snape's reaction could be multi - faceted. He might start by investigating the abuse more deeply. He could use his skills as a Potions master and a former Death Eater to find out who is behind the abuse. And then, he might take steps to ensure Harry's safety. This could involve enlisting the help of other teachers or even trying to get Dumbledore more involved. He may also start to teach Harry some extra skills or give him potions to help him deal with the emotional and physical trauma of the abuse.
In this kind of fanfiction scenario, Snape might initially be conflicted. On one hand, he has his long - standing dislike for James Potter, Harry's father. But on the other, his sense of duty as a Hogwarts professor could kick in. He might reluctantly start to heal Harry, all the while muttering under his breath about how much trouble Harry always seems to get into, just like his father. Then, as he heals Harry, he might start to see some of Lily, Harry's mother, in him and soften a bit.
In such a fanfic, Snape might initially be shocked. Given his complex relationship with Harry in the original series, he could struggle between his old grudges and his sense of duty. He might take it upon himself to protect Harry secretly at first, perhaps by using his position at Hogwarts to keep an eye on Harry's abusers. For example, if it's the Dursleys abusing Harry, Snape could find ways to make sure they don't go too far without revealing his true intentions.
One place to look could be Archive of Our Own (AO3). It has a vast collection of fanfics, and you can search for ones with this specific plot. Just use the search bar and type in relevant keywords like 'Snape finds abused Harry'. Another option is Fanfiction.net, though the tagging system there might require a bit more digging to find exactly what you want.
He could be secretly worried. Snape might use his knowledge of potions and dark magic to try and find a cure or at least a way to stop the bleeding. He may also be conflicted, as his past relationship with Harry and his loyalty to different sides in the wizarding world play a role in how much he wants to help Harry.
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.
For Harry, saving Snape could make him more empathetic towards Snape's past actions. He might start to understand the complex web of loyalties that Snape was caught in. It could also make Harry more confident in his ability to make moral decisions independent of others' opinions.
At first, it's likely to be very tense. Snape has always had a grudge against Harry because of his father. But as they live together, they start to see each other's true selves. Harry might see Snape's vulnerability and intelligence, while Snape might see Harry's courage and determination that are different from James's arrogance.