His social skills might be different. Instead of the somewhat naive Goku we know, he could be more aware of social norms. Bulma could teach him about proper behavior, but at the same time, his Saiyan impulsiveness would still shine through at times. So he might be a strange mix of a well - mannered person in some situations and a wild fighter when provoked.
His character would develop a more strategic side. Beerus is a very strategic fighter, and Goku, being raised by him, would learn to think more before acting in battles. He would also become more aware of the power hierarchy in the universe at a younger age, which could make him more cautious or more ambitious, depending on how you look at it. Additionally, his Saiyan pride might be tempered by Beerus' teachings, making him more of a team player in some ways.
The story could involve Goku having a more modern upbringing. Bulma's family is wealthy, so Goku might live in a big house and have access to all kinds of luxuries. However, he would still have his Saiyan nature. So there could be a conflict between his Saiyan instincts for fighting and the more civilized life Bulma tries to give him. Maybe he would be sent to a normal school and have to deal with bullies, but he would use his Saiyan strength in unexpected ways.
His power would develop more in line with Saiyan traditions. He'd probably have a stronger base power due to the intense training environment on Planet Vegeta. There would be more emphasis on raw power and combat skills from a young age.
Harry's character would become more centered around self - improvement. Goku is always striving to get stronger. So Harry would constantly be looking for ways to improve his magical and physical skills. He might not be as reliant on his friends for support in difficult situations as he is in the original story, instead trying to handle things on his own more often. This could make him seem a bit more independent and self - sufficient.
In the fanfiction, their relationship might start off as a bit of a shock to both of them. But gradually, they begin to respect each other more. Goku starts to see Bulma's intelligence and how it can benefit their family and the world. Bulma, on the other hand, comes to admire Goku's unwavering sense of justice and his strength. They communicate more often, sharing their thoughts and dreams. For example, Goku might tell Bulma about his Saiyan heritage in more detail, and Bulma might share her latest scientific ideas with Goku. This sharing helps them grow closer together.
The story could start with Goku being pushed to his limits by Goku Black's attacks. But then, he remembers his training with the Kai's and how they taught him to focus his energy in a more efficient way. He then uses this knowledge to create a more powerful Kamehameha that breaks through Goku Black's defenses and kills him.
Their relationship could develop in a very interesting way. Given Naruto's background of being an outcast in his village at first, he might be a bit hesitant to fully embrace Goku as a brother. But Goku's open - heartedness would gradually break down those barriers. Goku would introduce Naruto to his friends in the Dragon Ball world, and Naruto would do the same in the ninja world. They would start to share their stories, like Naruto's fight against Pain and Goku's battles against Frieza. Through these shared experiences, they would grow closer and closer, until they are inseparable brothers who are ready to take on any threat to their combined worlds.
In fanfiction, Goku Black's interaction with Bulma can be very different from the original series. Sometimes, he may start off as hostile towards her, given his nature as an antagonist. But as the story progresses, he could develop a grudging respect for her intelligence. For example, if Bulma is trying to create a device to stop him, he might admire her tenacity in the process.
If Naruto is trained by Goku in fanfiction, his character would experience significant growth. Naruto is already a determined character, but Goku's training could make him even more so. He would learn to value hard work in a different way. His relationships with his friends might also change as he becomes more self - reliant in his training. Additionally, Naruto's sense of justice could be broadened by Goku's more universal view of protecting the innocent. He would no longer just be focused on his village but on a larger scale of good and evil, making him a more well - rounded and developed character.
His character would become more confident. With Goku's support and the newfound power from being in the Dragon Ball universe, Naruto would have less self - doubt. He'd be more eager to take on challenges.