Don't forget about the power levels. In a crossover fanfiction, it's important to balance the powers. If Goku is in a world with less powerful characters, don't make him overpowered to the point where there's no challenge. Instead, find ways for him to be restricted, like maybe the new world has a different type of energy that he has to learn to control before using his full power. This way, the story remains interesting and the other characters can still play important roles.
Another option is a crossover with a different anime world, like Naruto. GT Goku could end up in the Hidden Leaf Village. The shinobi would be amazed by his power. Goku, being Goku, would be interested in learning their ninja techniques. They could team up against a common enemy that somehow has the ability to use both chakra and ki, creating a unique and exciting battle scenario.
Baby Goku in GT fanfiction is significant because he allows writers to explore uncharted territories of the GT universe. His character can be used to create new plot twists and turns.
Baby Goku in GT fanfiction can be a really interesting concept. A lot of times, authors will play with his Saiyan nature more. They might show him struggling with the dark side of his Saiyan instincts, which was somewhat present in the GT series but can be expanded upon in fanfiction. This could lead to some really cool character development and new story directions.
Well, perhaps in the fanfiction, Goku discovers a way to tap into a spiritual connection with Baby GT. Since Goku has a pure heart and strong spiritual energy, he could use this to his advantage. By establishing a link, he can send commands directly to Baby GT's mind, just like how some telepathic abilities work in the Dragon Ball universe. Another possibility is that Goku finds an ancient relic or spell that grants him the power to control Baby GT's actions.
One possible fanfiction could be Gt Goku traveling back in time to prevent the destruction of Earth in an earlier timeline. He could use his knowledge from the GT era to stop a powerful enemy that was previously victorious.
Well, for the characters' interaction, focus on their goals. Batman's goal is to protect Gotham, and the Winchesters' is to hunt down the supernatural. When they interact, these goals can either clash or align. For instance, if there's a supernatural threat in Gotham that the Winchesters are after but Batman doesn't fully understand the nature of it yet. There will be some tension as Batman tries to maintain his control over the situation in his city. But as they communicate, they can find common ground. You can also use their different ways of speaking. Batman is more formal and the Winchesters use a lot of slang, which can create interesting dialogue exchanges.
First, understand the characters well. Know Goku's Ultra Instinct powers, his personality, his goals. Then, when choosing a crossover universe, pick one that has elements that can contrast or complement Goku's world. For example, if it's a magic - based universe, how would Goku's physical powers interact with magic? Keep the story focused on the main characters and their development throughout the crossover.
The characters could interact in many ways. Goku could have a friendly sparring match with Captain America. Cap would be impressed by Goku's power and fighting skills, and Goku would respect Cap's leadership and unwavering will. Or Goku could help Iron Man upgrade his suit with some of his Saiyan technology knowledge.
In fanfiction, Goku's brain control of Baby GT can have a huge impact on the story. It could lead to unexpected plot twists. For example, Goku might use this control to turn Baby GT's power towards good instead of evil. This would completely change the power dynamics in the story and the relationships between characters.
To develop Goku Jr's character further, he could be given more complex emotions. For example, showing his fear in the face of truly overwhelming enemies, rather than always being fearless like Goku. This would make him more relatable. Also, exploring his relationships in more depth, like his friendship with Pan. Maybe they have a falling out over different views on how to protect their world, which forces Goku Jr. to grow and understand different perspectives.