Gohan might form a mentor - like relationship with some of the younger Fairy Tail mages. He has a lot of combat experience and could teach them about discipline and the importance of training. He could also be friends with the more powerful mages, like Natsu, and they could spar together to improve their skills.
He could potentially have a rivalry with some of the Fairy Tail members who are prideful in their strength. For instance, Gajeel might see Gohan as a threat and want to prove himself stronger. On the other hand, Gohan could form a close bond with Levy, as she is intelligent and could be interested in learning about Gohan's different world. Also, he might be seen as a big brother figure to Wendy, given his kind nature and his ability to protect others.
Sora would probably form really friendly relationships. He's a very positive and kind - hearted character. He'd likely get along well with Natsu because they both have a lot of energy and a strong sense of justice. He might also be friends with Lucy as she is friendly and open - minded, and they could share stories about their different adventures.
He could have an interesting relationship with Natsu. Natsu is known for his hot - headedness and love for a good fight. The Hulk, with his anger - based power, could be a great sparring partner for Natsu. They might start off as rivals, constantly trying to outdo each other in terms of strength. Or they could become friends who understand each other's need to let out their pent - up energy. He could also have a relationship with Lucy. Lucy might be a bit intimidated by him at first, but as she gets to know him, she could see his good side and try to help him control his anger. Maybe she could use her celestial spirits to calm him down in some situations.
Goku would probably get along well with Natsu. They both have a love for fighting and a strong sense of justice. They might constantly challenge each other to friendly battles to see who's stronger.
Gohan's powers could be a great addition to the Fairy Tail universe. His Saiyan strength and ability to go Super Saiyan would make him one of the most powerful mages in the guild. He could use his ki blasts like powerful magic attacks, and his speed and agility would be useful in battles against dark guilds.
The plot could involve Gohan getting transported to the Fairy Tail world. Maybe he'd join the guild and use his Saiyan powers in their quests. He could team up with Natsu and the gang, and his super strength and ki blasts would be a huge asset in battles against the dark guilds.
Probably Natsu. They both have a strong sense of justice and are very powerful fighters. Natsu's fire - based attacks and Gohan's ki blasts could make for some amazing combined attacks in battle.
Naruto would form diverse relationships. He has a very friendly and determined personality. So, he could bond with Issei, the main character in Highschool DxD. They could share their experiences of growing in power and facing challenges. With the female characters in DxD, Naruto would probably be respectful and friendly. He might form a brother - like relationship with some of the male devils, especially those who value strength and loyalty. However, his relationship with the more traditional and strict angels might be a bit rocky at first, as they might view his powers as something not in line with their beliefs, but through mutual understanding, they could become comrades.
In a modern society, Zuko could form romantic relationships too. He would be attracted to someone with a kind heart and strong values. His relationship would start slowly as he's not used to modern dating customs. He would be very protective of his partner. And his partner would have to understand his past and the fact that he's still adjusting to this new world. They would grow together, learning from each other's different backgrounds.
Edward could form strong friendships with the hobbits. Hobbits are known for their loyalty and kindness. They would be curious about Edward and his abilities. Edward, in turn, would appreciate their simple yet warm - hearted nature. He could help them in their adventures, using his alchemy skills, and they could offer him a sense of home and community that he might be missing from his own world.
He would probably form some interesting friendships. He might befriend people who are into martial arts or those with a sense of justice like him. He could also have a mentor - like relationship with some, teaching them about his ninja ways.