In some fanfictions, Draco might have a change of heart due to his hidden feelings for Hermione. He could use his knowledge of the Death Eaters' plans and Voldemort's weaknesses to rescue her. Maybe he has some secret magic or an unexpected alliance that helps him get to Hermione just in time.
In many fanfictions, Snape saving Hermione from Voldemort can be a very interesting plot. It could be due to Snape's complex character. He was a double - agent in the original series. So, in fanfiction, his loyalty to Dumbledore might drive him to protect Hermione, who is an important part of the good side against Voldemort.
Love. In fanfictions, it's a common motivation. Draco might have fallen in love with Hermione over time, and that love drives him to risk his life to save her from Voldemort.
Draco might be motivated by jealousy. He could be jealous of Ron and Hermione's friendship or a possible romantic relationship between them. So he tries to harm Hermione out of spite.
Well, perhaps Snape uses his position as a teacher to step in. He could have been observing the situation secretly and when Draco was about to do something harmful to Hermione, Snape intervened with a firm command or some magic spell to stop Draco in his tracks.
One possible motivation could be that Draco has changed. He might have seen the error of his ways and decided to do the right thing. Another motivation could be that he has feelings for Hermione, even if they are not fully realized yet. He doesn't want to see her in a bad situation, so he steps in.
In some fanfictions, Draco might save Hermione from Bellatrix out of a new - found sense of morality. Maybe he has grown tired of the Dark side's cruelty. He could see Bellatrix about to harm Hermione and use his knowledge of the Death Eaters' ways to create a distraction. For example, he might pretend that there is an intruder in another part of the manor, causing Bellatrix to leave Hermione momentarily, giving Hermione a chance to escape or for Draco to help her further.
In fanfiction, the scenario of Draco saving Hermione from Viktor can be quite complex. It might be part of a larger plot where Draco is secretly working against some dark forces that Viktor has unknowingly become involved with. Hermione could be a key target, and Draco, having some inside information, decides to protect her. This could lead to a whole new relationship dynamic between Draco and Hermione, as she now sees him in a different light, and Draco starts to question his own allegiances.
Well, in some versions, Ron might use his quick wit and knowledge of Hogwarts' secret passages to outmaneuver Draco. He could lead Hermione to safety through a passage that Draco doesn't know about.