The idea of redemption for Black Goku can also be a great concept. Maybe in the fanfiction, Goku tries to reach out to Black Goku and show him a different path, leading to a transformation of Black Goku's character.
One interesting concept could be the power dynamics. Since Black Goku is a powerful and often malevolent version of Goku, exploring how their powers interact in a fanfiction can be exciting. For example, they might have an epic battle where their similar yet different fighting styles clash.
In fanfiction about Goku and Goku Black, a common concept is the alteration of their power levels. Writers may give Goku new forms or boost Goku Black's abilities in unexpected ways. There can be stories centered around Goku Black's adaptation to the main timeline's culture and society. For example, he might have to deal with the everyday life in addition to his evil plans. And there are fanfictions that focus on the psychological impact of their battles on each other, like how Goku might be affected by constantly facing an evil version of himself.
One interesting concept is exploring Goku Black's backstory more in - depth. Maybe he has some hidden motives that were not fully explored in the original series.
One idea could be that Goku and Goku Black are forced to team up against an even greater threat from another universe. They start to understand each other's fighting styles during the battle and gradually develop a grudging respect for one another.
One interesting concept could be exploring Goku Black's origin in more depth. Maybe he has a hidden past or a different motivation for his actions that wasn't fully explored in the original story.
The transformation aspect could also be explored. Goku Black has his different forms in the Dragon Ball series. In RWBY fanfiction, these forms could be affected by the Aura or magic in the RWBY world. Maybe his Super Saiyan forms could be enhanced or restricted by the unique rules of RWBY.
One interesting concept could be exploring Goku Black's origin in more depth. Maybe he has some hidden motives or a different backstory that wasn't fully explored in the original series. Another concept could be his relationships with other characters. For example, how he interacts with the Z - fighters in a more complex and nuanced way in the fanfiction world.
One interesting concept could be a crossover battle. Imagine Goku's Saiyan powers against Naruto's ninja skills. Another could be a team - up where they face a common enemy that neither could defeat alone, like a super - powerful alien - ninja hybrid. Also, there might be a story about them training together and learning from each other's fighting styles.
Another concept might be the interaction between their different worlds. How would Naruto and his friends react to the Saiyan culture? And vice versa, how would Goku and his comrades deal with the shinobi world? It could lead to some really fun and unique storylines.
One interesting fanfiction could be about Goku and Black Goku teaming up against an even greater threat from another universe. In this story, they might initially be at odds but gradually learn to work together, using their unique abilities to save the multiverse.
In some fanfictions, a possible plot is that Android 21 discovers a way to transfer some of Goku Black's power into herself, creating a new form for her. This form has a mix of her android features and Goku Black's dark energy, leading to a whole new set of adventures as she tries to control this power.