One possible plotline could be Cell adjusting to his new female form. He might face different reactions from the other Z - fighters. For example, some might be more sympathetic while others are more suspicious.
Cell's self - image would be a major factor in her character development. She would have to deal with how others perceive her as a female and also how she perceives herself. This could lead to her evolving in ways that are very different from the male Cell. She might focus more on her appearance or use her femininity as a tool, either for good or bad, which would add new layers to her character.
The theme of transformation is also popular. It could be a physical transformation of the female Cell, or a more emotional and mental one as she navigates the complex world of DBZ, often changing from a more villainous or neutral stance to a more heroic one.
If Goku and Female Cell interacted, it could change the perception of enemies in the DBZ universe. Their cooperation might lead other fighters to be more open to the idea of redeeming former foes. For example, if they manage to work together successfully, Vegeta might rethink his stance on some of the villains he's faced.
Another plot could involve Female Cell having a premonition of a great threat to the universe. She approaches Goku because she believes his power and pure heart can help. Together, they embark on a journey to find the source of this threat. Along the way, they face various challenges that force them to rely on each other, leading to a growing bond between them.
One interesting fanfiction could be where Cell somehow ends up in the Naruto universe. Maybe he's a new type of enemy that the ninja have to face. It could bring a whole new level of danger as his powers are different from the normal jutsu - based attacks in Naruto.
One idea could be to explore what if Gohan had a different training partner before the Cell Games. For example, if Piccolo had trained with him more intensively, it might have changed his power level and fighting style during the games.
Maybe in the fanfiction, Cell could be re - created in a different form with a mix of other characters' DNA. He could have some of Piccolo's regeneration abilities along with Gohan's hidden power. This would lead to a whole new set of battles and power - level dynamics as the Z - fighters try to figure out how to deal with this new Cell.
One possible fanfic could be about Goku's intense training before the Cell Games. He might be shown pushing his limits in the Hyperbolic Time Chamber, trying out new techniques and forms to defeat Cell. Maybe he discovers a new power level that no one, including himself, expected.