The story would likely start with chaos as Goku's sudden appearance would be a huge shock. His actions would drive the plot. For example, if he accidentally destroyed part of a village while testing his power, the ninja would either see him as a threat or try to get his help against other enemies.
In a Naruto fanfiction where Goku lands, it could change the entire power dynamic. Goku's friendly and competitive nature would likely lead him to spar with the strongest ninja. He could also become friends with Naruto, who shares his determination. Goku might introduce new training methods to the ninja world, based on his own intense training regime on Planet Vegeta and with King Kai. His presence could inspire the ninja to reach new levels of power, or it could cause some to fear his overwhelming strength.
If Goku Black fuses with Goku in fanfiction, the story would progress in a complex way. The fused form might go on a journey to understand itself. Since it has two very different personalities combined, it would face a lot of internal conflict. This could be used to explore themes like identity and the struggle between good and evil. Externally, the fused Goku could attract new enemies who see it as a threat to their power or plans.
If Naruto fused with Bardock in fanfiction, the story would likely take a very different turn. At first, Naruto might be confused by his new abilities and instincts. He would need to train to master them. As he does, he would become a more prominent figure in the ninja world. He could potentially change the balance of power. Enemies would be more afraid of him, and allies would look to him for leadership. His journey would be about not only protecting the village but also about understanding his new Saiyan heritage.
The story might progress in a way that Azula uses Naruto for her own purposes at first. Maybe she wants to use his unique abilities in the ninja world to gain an advantage in her own world. But as she spends more time with Naruto, she starts to develop real feelings for him as a surrogate son. This would lead to a change in her character as she becomes more protective and less self - centered.
If Naruto turned into a zombie in fanfiction, the story could progress in several ways. One way is that his zombification could be part of a larger, darker plot. Maybe Orochimaru or some other villain has a hand in it. His friends would then need to search for a cure while also protecting the village from his zombie attacks. Another aspect could be that Naruto's zombie form has some unique abilities that make him both a danger and a mystery. This could lead to different characters trying to understand and control his new powers for their own purposes.
The story could progress with Naruto having to deal with the challenges of his new form. Maybe he has to find a way to reverse the transformation, so he goes on a quest to find a cure. Along the way, he meets old friends and new characters who either help or hinder him.
The story could start with Naruto suddenly finding himself in a giant form. Then he has to quickly figure out how to move without causing too much destruction. As he gets used to his new body, he might start using it to protect the village from threats that normal - sized ninja couldn't handle.
The story might progress with Fuu adapting to the Leaf Village's lifestyle.
They would likely have a very strong bond. Since they are brothers, they would support each other in battles and in their personal growth.
If Goku landed somewhere else, it would likely lead to a whole new power-up journey for him. He might discover unique training methods or face challenges he never imagined before.