They often interact as powerful allies. They respect each other's strength since they are both the result of fusing two extremely strong Saiyans. For example, they might exchange fighting techniques or strategies.
Regular Dragon Ball fanfiction usually focuses on battles, power - ups, and the main storylines from the original series. However, Vegito harem fanfiction centers around relationships. It's more about the emotional connections between Vegito and the multiple characters in his harem. The focus shifts from fighting villains to exploring the interactions and romances within the group.
A fanfiction could explore Gohan's Ultra Instinct in a training scenario. He could be training with Piccolo or Vegeta, and they are both amazed and a bit envious of his ability. Gohan then uses his Ultra Instinct to help them understand new ways of fighting and power - up techniques. This would strengthen their bonds as comrades and also make them more formidable as a team in future battles.
One popular theme is the power dynamics within the harem. Since Vegito is extremely powerful, the relationships often involve his dominance in a sense, but also his need to balance the different personalities in the harem. Another theme is the exploration of different characters' reactions to being part of a harem. For example, some characters might be initially resistant but gradually come to accept it as they develop deeper feelings for Vegito. Also, the cultural and species differences of the harem members can create interesting storylines, like how they interact with each other and with Vegito given their diverse backgrounds.
Often, fanfic writers will create a scenario where the training methods from Naruto are applied to Dragon Ball characters to help them reach Ultra Instinct. Maybe a Dragon Ball Saiyan goes through Naruto - style chakra control training which in turn helps in mastering Ultra Instinct. It's all about creative and wild ideas in fanfiction.
In some fanfictions, Gogeta and Vegito might find themselves in a different dimension where the rules of power and combat are different. They would need to adapt quickly. For example, they may lose their ability to fuse at will and have to rely on their individual skills more. This would lead to a great character - development arc for both of them as they learn to fight in new ways.
Vegeta is also very popular. His fans often write fanfiction where he either rivals Goku in achieving Ultra Instinct or develops his own unique form that is just as powerful. His pride and determination make for great storylines in the context of Ultra Instinct.
A group of rogue Saiyans from a parallel universe might also be antagonists. They see Goku's Ultra Instinct as a threat to their own plans of universal domination. They have their own unique powers and battle tactics, making them a formidable foe for Goku and his friends.
If Vegito stayed fused, it's likely that he could have overpowered the villains with his combined strength and skills. There might have been fewer challenges and a quicker resolution to the conflict.
One idea could be exploring how Goku further masters Ultra Instinct in ways that are different from the canon. For example, he might have to face an enemy that can nullify his normal Ultra Instinct attacks, so he has to find new ways to use it, like combining it with Kaioken.