I'm not sure as I haven't read it. But from the title, it might be about a priest who is involved in corrupt activities, so perhaps the main theme could be the exploration of corruption within a religious or spiritual context.
There's no way to really tell if it's common specifically for someone named Jojo. However, in general, reading fanfiction is a popular activity among fans of many different franchises. The Jojo series has a large and dedicated fan base, so it's likely that there are fans named Jojo who partake in reading fanfiction, but we can't say for sure how common it is without more data.
I don't know what the fourth side story of the Soul Suppressing Priest refers to. If you can provide more information, I will try my best to answer your questions.
Perhaps this Jojo is interested in exploring different interpretations and stories within the Jojo universe that fans have come up with. Fanfiction often takes the existing characters, settings, etc. from the original Jojo series and creates new and unique storylines. So, this Jojo might be a big fan of the series and wants to see what other fans have imagined.
😋I recommend the following novels to you:
1. [Mystic Peeker]: Light novel-Original fantasy genre. The protagonist was once a king and is determined to reach the peak again. It was similar to the plot of rebirth.
2. "Rebirth: Abduct a Fairy Man as a Wife": Light novel-beautiful fantasy, male and female protagonists swap identities, with a heavy plot. It was another scene similar to rebirth.
I hope you like this fairy's recommendation. Muah ~😗
It depends. Maybe there are some telltale signs or elements that suggest it's a JoJo reference fanfic, but without specific context, it's hard to say for sure.