There are many 'Draco Saving Harry' fanfics out there. Some explore the idea of Draco having a change of heart due to a shared danger they face, like a dark wizard threat that only they can overcome together. It's interesting to see how the author builds the trust between them in these stories.
I recommend 'A Different Kind of Savior' where Draco uses his knowledge of dark magic to save Harry from a death - eaters' trap. It's a short but intense read.
One possible fanfiction could involve Harry finding out that Draco was wrongly imprisoned in Azkaban. Harry might use his influence and his skills as an Auror to dig deeper into Draco's case. He could discover evidence that clears Draco's name, like finding out that Draco was framed by some dark wizards who wanted to get rid of the Malfoy family's influence. Then, Harry would have to fight against the bureaucratic system of the Ministry of Magic to get Draco released.
For Harry, his friends in Gryffindor could be a bit confused at first. They know Draco is not exactly a friendly character. But overall, it could lead to a more united front against real threats in Hogwarts. The teachers might also take notice. Dumbledore, for instance, would probably be proud of Harry for showing such selfless courage, regardless of who he was saving.
He could be doing it out of a sense of justice. Despite his family's views, Draco might see that the way the Dursleys treat Harry is wrong and decides to step in.
The wizarding world would be in shock. The Malfoys are known for their dislike of the Potters, so Draco saving Harry would go against the family's reputation. It could lead to Draco being ostracized by some in the pure - blood community.
One consequence could be that he gains an unexpected ally in Draco. Draco might feel indebted to Harry and start to change his views towards him, which could lead to some interesting interactions between them in the future. This could also cause some tension among their respective groups of friends.
It could lead to a more amicable relationship. Draco might be initially shocked and then grudgingly grateful. This could start to break down the walls of their enmity. They might start to interact in a more civil way, like nodding at each other in the hallways instead of glaring.
One motive could be love. In a romance fanfic, Draco's feelings for Harry might be so strong that he is willing to go against Dumbledore. He doesn't want to see Harry hurt by anyone, including Dumbledore. Another motive could be redemption. Draco might be trying to atone for his past wrongs and sees saving Harry as a way to do that.
One consequence could be that the fan - fiction's plot takes a completely different turn. Instead of a romantic storyline between Ron and Harry, it might shift towards a more adversarial relationship between Draco and Ron as Ron might suspect Draco's motives for interfering. Another consequence could be that Harry becomes more indebted to Draco, which changes their dynamic in the fan fiction.