Maybe Harry Potter, as a female, could start to understand the struggles of house elves deeply. She might use her magic to try and improve their living conditions, like Hermione did with the 'Society for the Promotion of Elfish Welfare'. She could also form unique friendships with some house elves, leading to adventures within Hogwarts and beyond as they work together to change the traditional views of house elves in the wizarding world.
Another possibility is a group of Hogwarts professors who are very conservative in their views. They might believe that house elves should remain in their subservient positions and would try to stop Harry from making any changes. They could use their influence within the school to make things difficult for Harry and her friends as they try to advocate for the rights of house elves.
Well, perhaps Harry could start seeing the world from the house - elves' perspective. He might use his magic in new ways to improve their living conditions. For example, he could secretly create better living quarters for them in Hogwarts. He might also try to teach them some basic self - defense magic so they can protect themselves from the meaner wizards.
The house elf might be very grateful. Harry is known for his kindness, so the elf could see this as a chance for a better life. It might immediately start serving Harry with great enthusiasm, believing that Harry will be a fair and good master.
The fanfiction could focus on Lemon's backstory. Maybe she was once a part of a different wizarding family before coming to Hogwarts. And in this new environment, she has to adjust to the different dynamics among the other house - elves and the wizards and witches in the castle. She could be facing some discrimination from the other house - elves for being too friendly with the students.
If Harry becomes a house - elf, his character would develop in a way that he becomes more resourceful within the constraints of a house - elf's life. He would have to use his wits to get things done because house - elves have limited magic compared to wizards. Also, his sense of justice would be even stronger. He would be constantly looking for ways to break the chains of the traditional house - elf servitude, maybe by finding loopholes in the ancient laws that bind them.
There could be many possibilities. It might be an original character created specifically for the fanfiction. However, it could also be a well - known house - elf from the original series, like Dobby, who in the fanfiction somehow comes to be owned by Harry Potter in a different set of circumstances. Maybe Harry saves Dobby in a more complex way in this fanfiction and as a result, Dobby becomes his house - elf.
Well, perhaps the house - elf is constantly tidying up in really cool ways. It could be folding clothes by magic so that they are always perfectly creased, or it might arrange the books in Harry's library in a way that makes it easier for him to find the exact spell book he needs at any given time. And it could also have a special connection with the other magical creatures around the house, like communicating with the garden gnomes and getting them to stay in line without causing trouble.
Dobby is often very popular in fanfiction. Since he was already a rather unique and brave house - elf in the original series, in fanfiction he can be portrayed in even more heroic or complex ways, like leading a revolution among house - elves.
Dobby would be a very likely candidate. He was already a prominent house elf in the original series and had a strong connection with Harry Potter. His brave and rebellious nature would make for great stories in a fanfiction where Harry is involved as a house elf too. Maybe they could have more adventures together, this time with Harry sharing Dobby's experiences.