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.
Character development is also crucial. In many such fanfictions, Female Goku Black may start as a villainous or at least antagonistic character. But as the story unfolds, she might change due to her interactions with Goku. This transformation can be really interesting to follow. For example, she could start to question her own motives or even develop feelings for Goku, which is a big shift from her initial stance.
As the story progresses, some fanfictions might explore a begrudging respect. Despite their differences, they recognize each other's power and fighting abilities. For example, they could have a series of battles where they start to understand each other's strategies better.
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.
Well, Goku Black could be the more dominant character. His dark nature gives him a different kind of power. He doesn't have the same moral constraints as Goku. This could allow him to make more ruthless and effective decisions in battle. He might be able to outmaneuver Goku if he plays his cards right.
Issei would be very likely. Since Issei is the main character in DxD, his curiosity and his own pursuit of power would make him interested in Goku. They could train together and learn from each other's abilities. Also, Rias would interact with Goku. As a powerful devil, she would be intrigued by Goku's power and his different way of approaching battles.
One popular 'goku x female goku black fanfiction' might be 'The Unlikely Bond'. It explores a unique relationship between Goku and Female Goku Black. In this fic, they start off as enemies but gradually discover they have more in common than they thought.
Well, a Goku x Caulifla x Kale fanfiction could potentially be about their adventures together in a new setting. Maybe it could involve them teaming up against a powerful enemy and during that time, their relationships grow and develop in interesting ways. However, 'lemon' usually implies some inappropriate or adult - themed content, which is not something I would encourage. So if we focus on a non - inappropriate version, it could be a story full of friendship and mutual growth.
Vegeta from the Dragon Ball series is often popular. Fans like to write about his reaction to Naruto's world and how he might interact with the characters there. Also, Sasuke from Naruto is frequently included. He could be a rival or an ally in the fanfiction, given his complex character. Another one could be Piccolo. His calm and strategic mind would be interesting to incorporate in stories involving Naruto's more chaotic ninja world.
In a Gohan x Goku fanfic, their relationship can be delved into by creating scenarios where they have to rely on each other completely. For example, if they are in a situation where Goku's strength and Gohan's intelligence are both required to escape. Their different personalities can also be highlighted. Goku's carefree nature contrasted with Gohan's more studious and responsible side. And of course, flashbacks to Gohan's childhood and how Goku's presence or absence affected him can add depth to their relationship.