Well, in 'jojo bizarre adventure gamer fanfiction', a cool concept might be the inclusion of characters from the game world into the jojo universe. They could interact with the jojo characters and bring new storylines. It could also involve the use of game items in the jojo world, like using a magical game sword against a stand user.
Jonathan Joestar is often popular. His noble nature can be interesting to explore in a gamer fanfiction context, like how he would adapt to game - like challenges.
Once upon a time in the world of Jojo, Jonathan Joestar was on a quest. He had to face the evil Dio. One night, as he was resting in an old, spooky mansion during his journey, he heard strange noises. But he wasn't afraid. He knew his Hamon powers would protect him. He got up, and with his brave heart, he explored the mansion. In the end, he found out it was just a stray cat that had made all the noise.
Well, the 'jojo's bizarre adventure novel' has a really complex plot. It spans generations of the Joestar family. There are different arcs, like the one where Dio Brando is a major villain. He has his own evil plans which often put the Joestars in great danger. And the characters keep evolving and facing new challenges in different locations around the world.