I'm not sure about a lot of fanfictions specifically with this title, but generally in fanfiction, if Snape takes advantage of Harry, it could be in terms of using Harry's position or power. For example, in some stories, Snape might use Harry's connection to Dumbledore to further his own ends within the wizarding world. However, this often leads to a lot of character development and plot twists as Harry realizes what's going on and either fights against it or tries to understand Snape's true motives.
One popular fanfiction in this theme might be 'A Dark Path'. In it, Snape's actions towards Harry are complex and seem to border on taking advantage, but as the story unfolds, there are deeper motives at play. Another could be 'Twisted Intentions' where Snape's behavior is initially misconstrued as taking advantage, but it's later revealed to be part of a grander plan to protect Harry.
These fanfictions usually develop their plots in a way that shows the darker side of Snape's character. At first, Snape might use Harry's fame as 'The Boy Who Lived' to his advantage. He could be using Harry to gain influence within the wizarding community or to get closer to the secrets that Harry might hold. As the plot develops, the relationship between them becomes more strained. Harry might start to question Snape's intentions and try to break free from his influence. This can lead to a series of events where both characters have to face their own demons and the consequences of their actions. There could be a climax where Harry finally stands up to Snape and exposes his true motives, or there could be a more complex resolution where Snape has a change of heart and tries to make amends for his actions.
There's 'Snape and the Deaged Savior'. In this fanfiction, Snape discovers deaged Harry in an unexpected place. He takes on the role of caretaker with his usual grumpy exterior but deep down shows a lot of care. He teaches Harry magic in a different way than the normal Hogwarts curriculum, which makes for an interesting read.
There might be a fanfiction where Harry takes care of Snape after a battle. He could be the one to tend to Snape's wounds, both physical and emotional. Since Snape has always been a rather closed - off character, Harry's attempts to get through to him and provide care could be a great source of character development for both of them. Harry might use his Gryffindor courage to break down Snape's walls.
You can try looking on Archive of Our Own (AO3). It has a vast collection of Harry Potter fanfictions, and it's likely that you'll find several stories about Harry taking care of Snape there. Just use the search function and type in relevant keywords like 'Harry takes care of Snape' and you should get a list of relevant fics.
One common theme is redemption. Snape is often seen as a character in need of redemption in the original series, and taking care of Harry can be a way for him to achieve that. Another theme is the exploration of family. It shows a different kind of family dynamic than the traditional ones in the Harry Potter world. And there's also the theme of sacrifice. Snape might have to sacrifice his own interests or safety to protect Harry.
One popular 'Harry Snape' fanfiction could be 'The Unlikely Bond'. It explores a unique relationship between Harry and Snape that goes beyond their canon interactions. It delves into their shared experiences in the wizarding world and how they gradually come to understand and respect each other.
Well, 'Snape's Hidden Guidance' is a popular one. It focuses on Snape secretly mentoring Harry in the background, without Harry fully realizing it at first. The author does a great job of building the tension between their relationship. And there's also 'Mentor and Apprentice: Harry and Snape'. This fanfiction delves deep into the idea of Snape teaching Harry more than just magic, but also about life and the wizarding world's politics. It's a really in - depth read.
A popular one is 'Snape Courts Harry: The Forbidden Affair'. But don't let the title mislead you. It's not about anything improper. Instead, it's about Snape trying to befriend Harry in a rather strange courtship - like way. He gives Harry gifts that are related to magic and potions, which helps Harry in his studies and also starts to build a bond between them.
There's a fanfiction called 'Snape's Guidance'. It shows Snape using his expertise in potions and dark arts to tutor Harry in a way that the Hogwarts curriculum doesn't cover. It also explores the emotional side of their relationship as Snape has to overcome his dislike for James Potter when dealing with Harry. 'A New Start with Snape' is also great. In this, Snape starts tutoring Harry after realizing Harry's potential to defeat Voldemort, and it has some really exciting plot twists as Harry discovers new magical abilities under Snape's tutelage.
Well, there's 'Snape's Hidden Guidance'. In this fanfiction, Snape secretly mentors Harry in ways that Dumbledore never could. It gives a whole new perspective on their relationship. Then there's 'Harry and Snape: An Unlikely Alliance' where they are forced to work together against a new dark threat, and in the process, they begin to see each other in a new light. 'The Unspoken Understanding' is also a good read. It's about how Snape and Harry develop an unspoken bond that helps them both through difficult times.