They'd be shocked. Goku is a legend in the Dragon Ball world, so they'd be super excited and probably a bit scared too.
Gohan's classmates would most likely have a mix of reactions. Some might be star - struck and immediately ask for autographs or pictures. Others could be a bit intimidated by his powerful presence. There would also be those who are just curious and start asking a million questions about his powers, his battles, and his life on Planet Vegeta.
Goku's reaction could be a mix of shock and joy. On one hand, he has been on Earth for so long without any real family connection to his Saiyan side. When he sees his parents, it would be overwhelming. He would likely be in awe of his father, Bardock, given his father's reputation as a strong Saiyan. And he would be eager to bond with his mother, who he has never known. He might also feel a sense of belonging that he has been missing all his life.
Bardock is a tough and battle - hardened Saiyan. When he meets Goku, who has a more pure - hearted and friendly personality, there could be an interesting contrast. Bardock might be initially skeptical of Goku's 'soft' ways but then come to respect his strength which comes from his good heart. Goku, on the other hand, would be curious about his father and would try to show Bardock the value of protecting others, not just for the sake of battle like the Saiyans usually do.
Cell would be a great villain to include. His ability to absorb other beings and his complex personality make for an interesting dynamic with Goku and Gohan. There could be a scenario where Cell somehow returns and is even more powerful, forcing Goku and Gohan to team up again in a new and intense battle.
His relationship with Vegeta would also change. If Goku goes back to a time when they first met, he could try to befriend Vegeta right away instead of being enemies first. This would change the entire dynamic of their rivalry. They might become allies much sooner and train together, which would lead to both of them becoming even stronger at an earlier stage.
One idea could be Goku and Gohan going on a special training journey to a new planet with unique gravity and energy sources. This would force them to adapt and develop new techniques together.
At first, Naruto would likely be very curious. He'd be eager to learn about this new world of Dragon Ball Z through the fanfiction. As he delved deeper, he'd start to form his own opinions about the characters. He might admire Goku's pure heart and his never - ending quest for self - improvement, and perhaps think about how he can apply some of those qualities to his own life as a ninja.
Gohan's powers would probably be seen as extremely strange and almost magical to the ponies. His ability to fly without wings, shoot energy blasts, and his super - strength would be beyond their comprehension. They might initially be frightened of him, thinking he's some kind of dangerous being. But once they see he's there to help, they would be in awe of his powers and see him as a powerful ally.
Gohan's relationships would develop differently. Let's say he goes back to when he was a kid and meets his father, Goku, at a younger age. He'd have a different kind of bond with him. He could teach Goku things he learned in the future, and this would change how they interact. Also, his relationship with Piccolo would be altered. He might be able to train with Piccolo in a more advanced way earlier, leading to a stronger bond based on mutual growth and respect. Overall, Gohan would become more of a proactive and influential character in the past.
Gohan could become more of a leader. With the power of Super Saiyan 5, he would be one of the most powerful beings in the universe. Other Z - fighters might look to him for guidance and leadership. This could bring out a more assertive side of his personality. He would need to step up and make tough decisions for the greater good, which would shape his personality in a more authoritative way.
At first, Caulifla might be a bit intimidated by Goku's power. But as they train together, she would start to understand his techniques and philosophy of fighting. Goku would also learn from Caulifla's unique approach to battles. Their relationship could evolve into a deep bond where they rely on each other in tough battles. For example, Goku could save Caulifla from a near - death situation, and in return, Caulifla could come up with a creative battle strategy that helps Goku against a difficult opponent.