One common plot device is the use of magical artifacts. For example, a magical amulet that has protective properties could be given to Harry. This amulet might be able to detect the presence of the stalker and create a shield around Harry when the stalker gets too close.
The discovery of the stalker's true identity and using that knowledge against them is also a plot device. Maybe the stalker is someone with a hidden past or a vendetta. Once Harry and his allies figure out who the stalker really is and what they want, they can use that information to outwit the stalker. For example, if the stalker is being controlled by a more powerful dark wizard, they could find a way to break that control and thus save Harry from the threat.
Another way Harry could be saved is through the help of his friends. In the wizarding world of Snarry fanfiction, his friends like Hermione and Ron might notice the stalker situation. They could work together to create a plan. Maybe they would use a combination of magic and Muggle - like detective work. For instance, Hermione's research skills could help them find out more about the stalker's motives and weaknesses, and Ron's loyalty and courage would ensure they are there to physically protect Harry if needed.
One common way is through the power of friendship. Harry's friends, like Ron and Hermione, might be vigilant and notice the stalker's actions. They could then use their combined magic and wits to outsmart the stalker and save Harry.
In some Snarry fan fictions, Severus Snape himself might have saved Harry from the stalker. Snape, with his powerful magic and his new - found, albeit complex, feelings for Harry in the Snarry context, could have detected the stalker's presence and used his skills to fend off the threat. He has the knowledge and experience to deal with such dangerous situations, so he might have stepped in to protect Harry when he realized the danger Harry was in.
One common plot device is the introduction of a new mentor figure. This person could be an older student, a former Hogwarts graduate, or even a magical creature. They guide Harry in his studies, offer advice on how to handle difficult subjects and professors.
One common plot device is the discovery of ancient artifacts or prophecies that link Harry to Merlin. For example, a magical amulet that was once Merlin's might be found and react only to Harry. Another is the appearance of a character who knew Merlin in the past and recognizes Harry as his reincarnation.
A plot device could be Cedric getting involved in Harry's personal quests. For instance, if Harry is trying to figure out something about his parents, Cedric may insert himself into the situation, believing he can protect Harry better that way. He might also try to monopolize Harry's time for training or studying, which could lead to some tension between them as Harry might feel smothered.
One common plot device is mutual protection. For instance, if one of them is in danger from some dark wizards or a magical accident, the other steps in to save them. This act of heroism creates a bond of trust and friendship.
A typical plot device could be the influence of an outside force. Say, a kind wizard or witch comes to the Dursleys and makes them understand the importance of Harry and his magic, and then they start to love him. Also, it could be that Harry himself shows extraordinary kindness towards the Dursleys in a difficult situation, which melts their cold hearts and changes their attitude towards him.
One common plot device is the 'what - if' scenario. For example, what if Hermione had been the one to save Harry from the Dementors instead of his father's Patronus? This can lead to a deeper emotional connection between them. Another is the 'arranged - relationship' plot, where they are forced to pretend to be in a relationship for some magical reason, but end up falling in love for real. Also, the 'jealousy' plot device, where they get jealous of each other's relationships with other characters and realize their true feelings.
One common plot device is mind control. For example, Voldemort or some other dark force could control Harry's mind and make him kill Dumbledore without his full awareness. Another is a misinterpreted prophecy. Harry might think Dumbledore is endangering his life based on a wrongly understood prophecy.