Perhaps Severus takes care of Harry in a protective way. When other students bully Harry or he gets into dangerous situations at school, Severus steps in. This could be due to an underlying sense of responsibility he feels, or maybe a growing affection for Harry that he doesn't quite understand himself.
A great aspect could be Severus helping Harry with his emotional turmoil. Harry has a lot on his plate, and Severus, having his own troubled past, could offer some words of wisdom. He could share his experiences in a way that helps Harry navigate the difficulties of growing up in a magical world filled with danger and mystery. This would deepen their relationship and show a different side of both characters.
One great fanfic in this vein might be 'The Veela's Care' where Harry discovers Draco is a Veela in a rather unexpected situation. Harry's care for Draco in this story is shown through his protection of Draco from those who might want to take advantage of his Veela nature. It's a really heart - warming read.
There could also be a plotline where Hermione discovers some of Snape's past traumas and in trying to help him, they form a bond. Snape, out of gratitude and a newfound respect for her, starts to take care of her like a mentor. He shields her from the harsh judgments of other Hogwarts professors and students alike, and together they work towards a better future for the wizarding world.
In these types of fanfics, the relationship between Harry and Draco is central. Since Draco is a Veela, his powers and how they affect the relationship are important. For example, his allure might draw Harry in an unexpected way. Also, the challenges they face together, like dealing with the wizarding society's view of Veelas. Harry's care could involve helping Draco navigate these difficulties and come to terms with his identity.
Well, it could be about Snape feeling a sense of duty. Maybe after Harry loses his sight in a battle against the Dark Arts, Snape, despite their past differences, steps in. He might start by teaching Harry new ways to navigate Hogwarts using magic that doesn't rely on sight, like advanced sonar - like spells.
One common scenario is Snape protecting Harry from the Dark Arts attacks within Hogwarts. Another could be Snape helping Harry with his studies privately, especially in potions where Snape is an expert.
A common theme is the exploration of a new relationship. Since Harry is taking care of Draco, they have to interact in a different way than in the original series. Another theme is the discovery of Draco's veela side. It usually involves a lot of mystery and learning about this new aspect of Draco.
Severus would probably use his knowledge of dark magic and potions to protect Harry. He could create protective spells and potions that would shield Harry from any immediate threats. For example, he might brew a potion that makes Harry invisible to dark wizards for a short period of time.
Well, at first Harry might be very suspicious. But as Snape shows consistent care, Harry could start to see him in a new light. Maybe he realizes that Snape has more layers than he thought. He might begin to understand that Snape's past actions were more complex than just being mean to him.