You can try some popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including Dragon Ball where Goku and Jiren are from. Just use the search function and type in relevant keywords like 'Goku Jiren love' and you might find some interesting reads.
In this fanfiction, Goku vs Jiren is likely to be an epic battle. Goku's power with the Universe's Watch might bring new and unexpected abilities. Jiren, on the other hand, is an extremely powerful opponent. The fight could involve intense energy blasts, high - speed combat, and strategic maneuvers. It might also explore the growth of Goku's character and his newfound power in relation to Jiren's unwavering strength.
It could be Vegeta. Maybe Vegeta does something really underhanded like stealing Goku's senzu beans or trying to take all the credit for a victory that Goku also contributed to. Goku, being a fair - minded person, would get angry at such behavior.
In the fanfiction, the plot could develop such that the power of the universe's watch attracts other villains or powerful beings. They might try to steal the watch from Goku during his battle with Jiren. This would add a new layer of complexity as Goku has to fend off these new threats while still trying to defeat Jiren.
There probably is. Fanfiction is a vast world where all kinds of ideas are explored. Since Naruto and Jiren are from different anime universes, a fanfiction about Naruto being a fan of Jiren could be really interesting. It might involve Naruto somehow learning about Jiren's power and being in awe of it. Writers could play around with different scenarios like Naruto trying to train like Jiren or even seeking his advice in the fanfiction world.
Well, perhaps in the fanfiction, Goku gets mad when he discovers that someone has been using his name for evil deeds. This would go against his values of justice and protecting the innocent. He might get really angry and go on a search to clear his name and stop the impostor. Or it could be that a new, extremely powerful villain emerges and starts to destroy planets without any remorse. Goku, being the defender of the universe, would be enraged by such senseless destruction and would confront the villain with all his might.
One reason could be ChiChi's overbearing nature. She is often very strict about Goku's training and how he spends his time. In fanfiction, this could be exaggerated to the point where Goku finally gets fed up. For example, if she constantly nags him about not doing enough chores around the house instead of training, it might push Goku to his limit.