Well, one possible plot could be that Goku somehow ends up in the Fairy Tail world. He might initially be confused by the magic there, but then start to learn about it. He could team up with Natsu and the gang to fight against a powerful dark wizard. Goku's strength and his unique fighting skills like the Kamehameha could be a great asset to Fairy Tail in battles.
Erza would also be a good pairing. She is a very disciplined and strong - willed character. Goku could learn from her discipline, and she could learn from Goku's carefree yet determined attitude. They could fight side by side in battles and protect each other.
If DBZ Goku were in Fairy Tail, his sense of justice would fit right in. He could form strong bonds with the Fairy Tail members. His training regime might even influence some of the wizards to train harder. And when it comes to battles, his ability to sense energy would give him an edge over many foes. He could also learn some of the Fairy Tail magic techniques and combine them with his own powers in really interesting ways.
One possible plot could be that Goku somehow gets transported to the Fairy Tail world. He might initially be confused but quickly adapt due to his adventurous nature. He could team up with Natsu and the others to fight a common enemy, like a powerful dark guild that has a magic that can rival Goku's strength. Their combined powers would make for an epic showdown.
Well, one unique aspect is his power level compared to the Fairy Tail characters. Goku Black is extremely powerful, so in fanfictions, he can either completely overpower the Fairy Tail mages or he might teach them new ways to increase their strength. For example, his ki - based attacks are a completely different form of energy than the magic in Fairy Tail.
There could be a fanfiction where Goku is a long - lost relative of a powerful Fairy Tail wizard. In this story, he discovers his family ties while also having to face off against a common enemy that threatens both his Saiyan heritage and the Fairy Tail guild. He would bring his Saiyan strength and tenacity to the battles in the Fairy Tail world.
Well, Goku's powers are extremely powerful. In Fairy Tail, magic is the main power source. Goku's ki-based abilities could be seen as a super-advanced form of magic. His super strength, speed, and energy blasts could make him a formidable ally or a terrifying foe. He could easily take on some of the stronger dark guilds by himself. Also, his ability to constantly grow stronger through training would be a unique aspect compared to the mages in Fairy Tail who mainly rely on learning new spells.
Well, Goku's powers are mainly based on ki manipulation, which is somewhat similar to magic in the Fairy Tail world. If he joins Fairy Tail, he could probably learn to combine his ki with the magic of Fairy Tail. For example, he might be able to infuse his ki into Natsu's fire magic to make it even more powerful. Also, his teleportation technique, like Instant Transmission, could be a great asset during battles and rescue missions in the Fairy Tail universe.
One possible plot could be that Goku somehow gets transported to the Fairy Tail world. He could join forces with Natsu and the gang to fight against a common enemy like Acnologia. Goku's power levels would be off the charts compared to most in Fairy Tail, but he'd be intrigued by their magic. Maybe he'd learn some magic himself or teach them some of his ki techniques.
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.