Well, a great plot for the fanfiction could be a race between different characters in the Dragon Ball Super Macho Universe to collect all seven Dragon Balls for their own purposes. One character might want to use them to bring back a loved one, while another wants to use them to gain ultimate power. Along the way, there would be battles and alliances. Another idea is that a new form of Ki is discovered in the Macho Universe that only certain characters can master. This leads to a divide between those who can and those who can't, and a big conflict arises as a result.
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 exploring a new transformation that combines the power of multiple existing forms. For example, a fusion of Super Saiyan and Kaioken that gives the character an edge in battles. Another could be delving into the backstories of minor characters in the Macho Universe, like how they got their powers.
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.
One idea could be a story where Goku and Vegeta from Dragon Ball Super end up in the world of Dragon Ball GT by some sort of time - space rift. They then have to team up with the GT versions of themselves to fight a new, powerful enemy that is threatening both timelines.
In a Dragon Ball alternate universe fanfiction, there could be a plot where all the Saiyans survived the destruction of Planet Vegeta. They form an alliance with Earth and together they face new threats from a different galaxy. This would change the power dynamics completely. There could also be a scenario where the Kaioshin are the main antagonists. They use their divine powers in a corrupt way, and the Saiyans and Earthlings have to join forces to stop them. And what about a universe where the concept of ki is different? Maybe it can be transferred between people like a currency, and battles are fought not just with strength but also with strategic ki trading.
A character with the ability to transform into different elements like fire, water, or earth. This would add a new dynamic to the battles. Another could be a small, alien creature that has the power to control the minds of others, creating chaos among the heroes. There could also be a warrior from a lost civilization in the Macho Universe who has a unique fighting style that combines swordsmanship and Ki blasts.
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.
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.
Dragon Ball: Super Universe 2 didn't have a GT-themed plot. There were only GT-themed characters and costumes. The three evil dragons could be obtained in the form of Dragon Ball Wishes. The Super Four Goku, Vegeta, and Wujita could also be obtained by unlocking the PG quest, but this wasn't part of the GT-themed plot.
In Dragon Ball Z Macho Universe Fanfiction, Trunks is quite popular. His time - traveling adventures and his cool demeanor are appealing. Also, Piccolo. He has a unique look and his role as a mentor and powerful fighter is often explored in fanfictions. He has a lot of depth to his character that can be delved into.
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.