If Snape adopts Harry and Draco, it could change the whole dynamic of Hogwarts. Snape would have to ensure that both boys are getting proper magical education while also taking care of their emotional well - being. Harry might start to see Snape as more than just a teacher who was always tough on him. Draco would be forced to interact with Harry in a more positive way. There could be some really heartwarming moments as Snape tries to show his affection for the two boys in his own, rather gruff way. And perhaps they could all form a strong, if unconventional, family unit.
In such a fanfiction, the plot could involve Snape taking on the role of a father figure to Harry and Draco. He might use his knowledge and skills to protect them from the various threats in the wizarding world. Snape could also teach them advanced magic, which they might not learn otherwise in Hogwarts. And there would likely be a lot of emotional growth for both Harry and Draco as they deal with their new family situation and their past traumas.
They would probably become like brothers. With Snape as their common father figure, they would have to learn to get along. Harry might be more forgiving of Draco's past actions, and Draco would have to let go of his animosity towards Harry.
In the fanfiction, their relationship would be complex at the start. Snape, having his own demons and secrets, would be a bit of an enigma to Draco. Draco, on the other hand, would be dealing with the loss of his family's status. Snape would start by providing a stable home for Draco. As they interact more, Draco would notice Snape's small acts of kindness. Snape would encourage Draco to explore his own identity outside of the Malfoy name. This would lead to a closer relationship, with Snape teaching Draco about things like loyalty, sacrifice, and the true nature of magic, and Draco in turn bringing out a more human side of Snape.
One possible plot could be that Snape, seeing the troubled situations of both Harry and Draco, decides to take them under his wing. He could start by teaching them more advanced magic in a strict but fair way. Harry might initially be resistant as he has his own ideas about Snape, but gradually realizes Snape's good intentions. Draco, on the other hand, might struggle with the idea of being under Snape's authority as he is used to his family's influence. They could all learn to live together, with Snape guiding them through the challenges of Hogwarts and the wizarding world at large.
One possible plot could be that Snape, seeing Draco's vulnerability after the fall of the Malfoy family in the wizarding war, decides to take him in. Snape would then have to deal with Draco's emotional baggage and his own complex feelings towards the boy. He might try to teach Draco a different set of values than what he was brought up with in the Malfoy household.
Well, considering Harry, his relationship with the other Gryffindors could be affected. Some might think he has turned to the 'dark side' since he is now under Snape's care. But others might understand that Harry has no choice in the matter. Draco's relationship with Hagrid could be very interesting. Hagrid might be very cautious around Draco now that he is with Snape. And Snape's relationship with the other Hogwarts professors would also change. Some might be more understanding, while others might think Snape is overstepping his boundaries. But overall, these new family dynamics would cause a ripple effect throughout the wizarding world.
The relationship would be drastically different. Harry, who has always seen Snape as a rather unlikable figure, would start to see him in a new light. He might come to respect Snape as a father figure. Draco, who has some connection to Snape through his family, would now have a more personal and perhaps more positive relationship with Snape. Snape himself would have to soften his usual harsh demeanor towards Harry. And between Harry and Draco, they would be forced to get along better as they are now under the same roof. They might start to understand each other's insecurities and backgrounds more.
It could be an orphaned wizard child from a family that was killed by Death Eaters. This would give Snape an added sense of responsibility as he might feel guilty for being associated with the Death Eaters in the past.
Snape's character often develops from a cold and aloof figure to a more caring and nurturing one. At first, he might be hesitant and gruff, but as he spends more time with Harry, his protective instincts kick in. He starts to show more patience and understanding, which is a big change from his usual self in the original series.