Well, one possibility is that Harry discovers a new magical ability that allows him to make a familiar. He chooses Remus because of their strong bond. Then, they might have a deeper connection in battles, with Remus being able to sense Harry's needs and intentions more acutely. Maybe Remus could also gain some new powers or abilities as Harry's familiar, which would be really interesting to explore in the fanfic.
Remus might become more submissive in a way. Since he is now Harry's familiar, he has a certain obligation to follow Harry's lead. However, he would still retain his intelligence and wisdom. For example, in a battle, he might be more likely to wait for Harry's command rather than act on his own instincts immediately.
Well, it could lead to some really interesting magical adventures. Maybe Harry would have Remus in an animal form to help him with certain tasks or investigations. Remus, in his familiar form, might be able to access places that are difficult for humans to reach, providing Harry with valuable information.
One conflict could be the ethical implications of turning a human into a familiar. In the wizarding world, there are likely rules about this sort of magic, and Harry might face consequences for his actions.
The main characters would obviously be Harry Potter and Remus Lupin. Harry is the one who turns Remus into his familiar, so he is a central figure in this fanfic's unique plot. Remus, on the other hand, has his own complex identity as a werewolf and a former teacher at Hogwarts, and now he is in this new and rather strange relationship with Harry as his familiar.
Perhaps in this fanfic, there is some sort of danger in the wizarding world that can only be overcome by Harry and Remus having this special familiar - master relationship. Harry might turn Remus into his familiar to protect him from a dark force that is specifically targeting werewolves. As they navigate this new dynamic, they also have to deal with the reactions of their friends and the wizarding community at large. The story could explore themes of acceptance and the power of unconventional relationships.
In a fanfic where Harry Potter makes Remus Lupin his familiar, it could open up a whole new world of possibilities. First, it would redefine the concept of familiar in the wizarding world. Since Remus has his own complex backstory and relationships, it would add layers to Harry's character development. Harry might have to deal with the prejudice that some wizards have towards werewolves more directly. And Remus, in turn, would have a new role and purpose. He could be more protective of Harry, and they could communicate in a more instinctive way, similar to how a wizard and a traditional familiar communicate.
The story could develop in many ways. For one, Harry would have a constant companion in Remus who could offer advice based on his years of experience. Their bond might allow for some sort of magical connection where they can sense each other's emotions or danger. This would make their adventures more intertwined. Also, the wizarding community's reaction to such an unusual familiar would be an interesting plot point.
One possible fanfic could be about Remus Lupin's search for a permanent cure to his lycanthropy. It might involve him traveling to far - off places, meeting with ancient healers or magic users who claim to have the knowledge. Maybe he teams up with some of his old Hogwarts friends like Sirius or James in flashbacks, and they try to find a cure together. This would add an element of friendship and adventure to the story.
The characters. Harry, Hermione, Ron, and all the other characters are so well - developed that they are easily recognizable and beloved. Fanfiction writers often use these characters to create new adventures or explore different aspects of their personalities, which makes Harry Potter a familiar source for fanfiction.