A really interesting storyline could be that an ancient prophecy in the Fairy Tail world foretells the arrival of a being with ultimate power like Goku. The Fairy Tail guild is divided on whether to welcome him or be afraid. Meanwhile, there are other forces that want to use Goku for their own evil purposes. The story could revolve around Goku trying to figure out his place in this new world, while also having to deal with the various threats and the complex relationships within the Fairy Tail guild.
Well, it's really hard to say for sure. Ultra Instinct Goku is extremely powerful with his god - like reflexes and insane combat skills. But Fairy Tail characters also have some very strong magic. If we consider Goku's speed and strength, he might have an edge. However, some Fairy Tail mages could potentially use powerful spells to counter him. So it could go either way depending on how the fanfiction is written.
One possible plot could be that there is a rift in the multiverse that brings Goku and Luffy together in a strange new world. They initially misunderstand each other and start to fight. As the fight progresses, they both realize that there is a greater threat at hand that is causing the rift. So, they team up, with Goku teaching Luffy some of his combat techniques and Luffy showing Goku the value of friendship and loyalty in a different way.
One possible storyline could be that Goku gets Ultra Instinct right when Frieza is about to kill all the Namekians. He then uses his newfound power to completely overpower Frieza and save the day. Another could be that he gets it during a battle with the Ginyu Force and easily defeats them all in one go.
Another storyline could involve a character from UQ Holder learning the secrets of Ultra Instinct from Goku. This would be a great way to blend the two universes' concepts. The UQ Holder character could struggle at first to understand and master it, leading to some comical and also tense moments as they train with Goku. Maybe they have to overcome some personal limitations in order to even begin to access the power of Ultra Instinct.
Yes, it is possible. In fanfiction, writers have the creative freedom to reimagine the origin of characters. Goku being born with Ultra Instinct can add a whole new layer to his character development. It could mean that his power growth would be different from the original story, perhaps faster or with different challenges along the way.
You could write a fanfiction where Goku teaches others about Ultra Instinct. Maybe he tries to pass on this power to Gohan or Trunks. This would involve Goku having to understand the power more deeply himself in order to teach it, and it would also be a great way to develop the other characters.
Goku in Ultra Instinct mode is extremely powerful. He has superhuman speed, strength, and can dodge attacks effortlessly. However, Luffy also has his own set of amazing abilities like his Gear Fourth form which gives him enhanced speed and power. But I think Goku would win because his combat skills and power level are just on a different scale compared to Luffy.
Well, it could be about Goku's new Ultra Instinct form affecting his relationship with Chichi. Maybe she has a hard time understanding this new side of him at first, but then they grow closer as she learns to accept it.
One possible plot twist could be Goku traveling back in time to train with his past self. This would not only enhance his own power but also change the course of his past battles. For example, he could teach his past self Ultra Instinct earlier, leading to different outcomes against foes like Frieza or Cell.
A fanfiction could focus on Goku's relationships while in Ultra Instinct. For example, how does he interact with his friends and family? Does Vegeta view him differently? In this story, Goku might struggle to control the Ultra Instinct around his loved ones because it makes him seem so detached. This could lead to some interesting emotional moments between the characters.