There's also 'Diamond in the Rough'. This fanfic focuses on a unique relationship between the reader and a JJBA character. The writing style is very descriptive, especially when it comes to the Stand battles. It really brings the action to life and makes you feel like you're in the middle of the chaos.
First, you need to understand the JJBA universe thoroughly. Know the characters, their personalities, and the rules of Stands. For example, if you're writing about Jotaro, you have to capture his cool and aloof demeanor. Then, create a unique plot that involves the reader in a believable way. It could be that the reader has a Stand of their own and gets caught up in a battle against the main villains.
Well, often there's the theme of self - discovery. The hateful reader, through their experiences in the JJBA universe, might learn more about themselves and why they had such negative feelings in the first place. Also, power dynamics can be a theme. The JJBA characters have their own powers and abilities, and the interaction between the hateful reader and them in terms of who has the upper hand in different situations can be an interesting aspect of the story. There can also be themes related to forgiveness, as the characters may or may not forgive the reader for their initial hatred.
Well, you can try looking on some popular fanfiction websites like Archive of Our Own. Just search for 'jjba x hateful reader' there and you might find a good selection. However, the availability of such stories may vary depending on how many authors have chosen to write in this particular niche.
Another theme is the alteration of relationships. In these fanfictions, the relationships between the JJBA characters and the reader can be very different from the original. It could be a romantic relationship that was not present in the original series, or a friendship that forms in a very unexpected way due to the changes in the alternate universe.
One great 'jjba x reader alternate universe fanfiction' is 'A Different World of Stands'. It takes the reader into an alternate universe where the Stand abilities are used in unique and unexpected ways. The relationship between the main character and the jjba characters is really well - developed, making it an exciting read.
One interesting JJBA x MLP fanfiction could be where the Stand abilities from JJBA are introduced into the world of MLP. For example, a pony might gain a Stand that gives it unique powers, like the ability to control time in a small area, similar to DIO's The World. This could lead to all sorts of adventures and challenges within the pony world as they figure out how to use these new powers and face off against villains who also might get their hands on Stand - like abilities.
The JJBA manga is indeed finished. It had a great journey and wrapped up with a satisfying conclusion for fans. However, there's always the possibility of spin-offs or related works in the future.