One interesting plot idea could be the return of an ancient and powerful villain from the Dragon Ball universe that was thought to be long forgotten. This villain could have powers that even the Gods of Destruction are wary of, forcing Goku and his friends to train in new and extreme ways.
Another plot could involve a new form of fusion that combines more than two characters at once. This super - fusion would have unique abilities and a completely different appearance, and it would be a game - changer in battles against powerful foes. For example, fusing Goku, Vegeta, and Trunks together to create a super - powerful warrior.
A plot could revolve around a group of underdog fighters in Universe 2 who train in secret to enter the Tournament of Power. They face numerous challenges during their training, including a lack of resources and interference from more powerful groups. But through their determination and unique fighting styles, they manage to make a name for themselves in the tournament.
A plot could involve Cooler getting trapped in an alternate dimension where the rules of power are different. He has to figure out how to adapt and escape while also facing off against strange new foes. Or perhaps he discovers a long - lost relative who has a connection to Earth, and this forces him to reevaluate his stance on the planet and its inhabitants.
One idea could be a fanfic where Goku discovers a new form that is a combination of Ultra Instinct and Super Saiyan God. This form gives him unique abilities and a new look. Another idea is to have Vegeta go on a solo adventure to a new planet filled with powerful foes that force him to develop a new fighting style. Maybe also a story where the Z - fighters have to team up with their old enemies like Frieza to fight a greater threat from another dimension.
One idea could be a story where the Saiyan Blue form has an unexpected side effect. For example, it could start to drain the user's life force slowly but surely. Goku discovers this during a battle and has to find a way to either control it or reverse the effect while still fighting powerful foes.
One idea could be creating a new character who has a unique power that challenges the existing power hierarchy in the Dragon Ball Super universe. For example, a character who can manipulate time in a different way than Whis or Beerus. Another plot could involve a tournament where fighters from different universes have to team up in unexpected combinations. This would lead to new rivalries and friendships. And perhaps a plot where the Dragon Balls are used in a completely different way, like to restore a destroyed universe but with some unforeseen consequences.
One idea could be that a character from Naruto's world somehow gets transported to the Dragon Ball Super universe and ends up in a harem situation. For example, Naruto himself could be sent there and due to his unique abilities and charm, attract the attention of various female characters like Bulma, Android 18, and Chi - Chi. Another plot could involve a new villain who uses the concept of a harem to manipulate characters from both universes, forcing them to work together to overcome this strange threat.
One idea could be exploring the Grand Priest's past. Maybe he had a different role in the universe long ago. Another could be a story where the Grand Priest has to make a difficult decision that goes against the will of the Omni - King. Or perhaps a story where the Grand Priest trains a new character to become a powerful being in the Dragon Ball universe.
One idea could be that Goku from 'Dragon Ball Super' somehow ends up in a world full of lemon - like magical fruits that give him new powers. He has to learn to control these powers while also dealing with the strange inhabitants of this new world.
One common plot idea is a crossover where characters from Fairy Tail and Dragon Ball Super meet. For example, Natsu from Fairy Tail could team up with Goku from Dragon Ball Super to fight a powerful villain that threatens both their universes.
Perhaps a story where a previously unknown fighter enters the Tournament of Power. This fighter has been training in seclusion and has powers that are a combination of different techniques from various universes. They start off as an underdog but quickly become a force to be reckoned with, making allies and enemies along the way.