The Jojo series often has complex family relationships and loyalty themes. Jesus' teachings about love and brotherhood can be integrated here. A Jojo family might be torn apart by power struggles, and Jesus could come in and teach them the importance of loving one another as family. His presence could heal the rifts in the family, much like he healed the sick in the Bible, while also fitting into the family - centric themes of Jojo.
Maybe Jesus could be a mentor figure to one of the Jojo characters. He could guide them on their journey, not just in terms of fighting enemies with their Stands but also in terms of moral and spiritual growth. For example, he could teach them the true meaning of courage and self - sacrifice, which are important themes in both the Jojo series and the concept of Jesus.
The first stories about Jesus were likely written in the 1st century AD. It's a complex topic as different scholars have different opinions on the exact timing and sources, but this is a common estimate based on historical and religious research.
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.