Perhaps a magic spell in the Fairy Tail world goes wrong and creates a portal that sucks in some of the main characters from Dragon Ball Z. Vegeta, for example, would initially be angry about being in this strange new place but would soon realize that there are powerful foes and allies here. The Fairy Tail guild could hold a tournament to see who is the strongest among them and the Saiyans join in. This would lead to epic battles and also some comical moments as the two groups with very different cultures try to understand each other.
In a Dragon Ball Z and Fairy Tail crossover, the Dragon Balls could be the key. What if the Fairy Tail wizards discover the existence of the Dragon Balls? They might think they are some extremely powerful magical artifacts. Natsu, with his impulsive nature, would want to collect them all. At the same time, the Z - fighters are also on a quest for the Dragon Balls. This could lead to a race between the two groups. However, they soon realize that there are darker forces at work trying to use the Dragon Balls for evil purposes, so they must join forces to protect them.
A cool plot could be a tournament - style crossover. A powerful being from another dimension decides to host a tournament where fighters from Dragon Ball Z and Devilman are invited. Characters like Vegeta and Devilman's friend Akira Fudo would compete. There could be unexpected alliances and rivalries. For example, Piccolo might initially see Devilman as a threat but later realize they have a common goal of protecting their respective worlds. And in the end, they all have to team up against the true evil that the tournament organizer has in store.
A plot might involve the Dragon Balls being scattered across the Bleach universe. Ichigo hears rumors about these powerful orbs and starts looking for them. Meanwhile, Goku and his friends also end up in the Bleach world while searching for the Dragon Balls. They meet the Soul Reapers and at first there's some tension. But as they learn more about each other's goals, they work together. The Soul Reapers are fascinated by Goku's power and training methods, and Goku is intrigued by the concept of souls and the afterlife in the Bleach world.
A fanfiction could explore what would happen if Natsu from Fairy Tail learned the Kaioken technique from Goku in Dragon Ball Z. Maybe he uses it in a fight against a really strong opponent in the Fairy Tail world, but has trouble controlling the power at first, leading to some comical and intense situations.
One interesting pairing could be Goku and Natsu. Goku is all about power and the pursuit of strength, while Natsu has a similar drive. They could have some really intense training sessions together. Another cool pairing would be Vegeta and Gray. Vegeta's serious and often - cold demeanor could contrast with Gray's more laid - back but still determined attitude. And then there's Bulma and Lucy. Bulma's intelligence and technological know - how could pair well with Lucy's celestial spirit magic knowledge. They could work together to create some new gadgets or strategies.
Goku and Natsu would be an interesting pair. Goku is always looking for a strong opponent to fight and improve his skills. Natsu, on the other hand, is a hot - headed but powerful wizard. Their fighting styles are quite different. Goku relies on his martial arts and ki abilities, while Natsu uses his fire dragon slayer magic. They could learn a lot from each other. For example, Goku could teach Natsu about physical conditioning, and Natsu could show Goku some unique magical techniques.
A cool plot might involve a rift in space - time that pulls the Dragon Ball Z world and the DC Universe together. Vegeta could be at odds with Wonder Woman at first, seeing her as a rival in terms of strength and combat skills. The Justice League and the Z Fighters then discover that an ancient evil force from both of their universes' pasts has been awakened. They must learn to work together, with Gohan and Robin sharing their intelligence to figure out a plan. The Saiyans' transformation abilities and the Justice League's various powers like the Flash's speed would be crucial in the final battle against this evil.
One possible plot could be that Luffy and his crew are sailing in the Grand Line when they encounter a strange energy. It turns out to be a Dragon Ball. They then have to deal with various villains from both universes trying to get the ball. Maybe Frieza hears about it and teams up with some of the pirates from One Piece. And Goku, sensing the power of the Dragon Ball, also arrives in the One Piece world to help Luffy protect it.
In a Dragon Ball Z and Fairy Tail crossover, the power levels would be an interesting aspect. The Saiyans' ki - based powers are very different from the magic in Fairy Tail. However, they could find common ground. Maybe the Fairy Tail guild could teach the Dragon Ball Z characters about the importance of friendship and teamwork in a more in - depth way. And the Dragon Ball Z characters could show the Fairy Tail wizards how to train their bodies and minds to reach new levels of power. The fanfiction could explore how the two groups interact and learn from each other.
One possible plot could be that Thanos somehow gets his hands on the Dragon Balls. He wishes for the power to snap away half of all life in the universe even more easily. The Z - fighters sense this great imbalance and travel to the Marvel universe to stop him. Goku, being the most powerful Z - fighter, tries to fight Thanos but quickly realizes his strength is different from what he's used to. Vegeta might have to team up with Iron Man to come up with a technological way to counter Thanos' Infinity Stones while Goku trains to reach a new level of Super Saiyan to take on Thanos directly.
Perhaps the Dragon Balls get scattered across the Yu - Gi - Oh world. Yugi and his friends, along with Goku and the Z - fighters, have to search for them. But there are evil forces in the Yu - Gi - Oh world that want to use the Dragon Balls for their own gain. So, they have to battle these foes while also dealing with the various challenges and mysteries of the Yu - Gi - Oh universe, like the different types of card decks and the power of the Shadow Realm.