There could be a fanfiction where Kefla has to team up with her former enemies to face a greater threat. In this story, she has to put aside her pride and work with others, which is a big character development for her. This would involve detailed battles and lots of dialogue to show the changing relationships among the characters.
Archive of Our Own (AO3) is also a good place. There are various fanfictions there. Just use the search function and type in 'Dragon Ball Super Kefla' to find relevant stories. It has a tagging system that helps you narrow down your search based on the type of story you want, like whether it's a romance, adventure or something else.
In this fanfiction scenario, it could be an extremely emotional encounter. Goku, who has grown so much in Dragon Ball Super, finally meeting his father Bardock. Maybe Bardock gets to see how his son has not only become a powerful Saiyan but also a protector of Earth. It could lead to some interesting exchanges about Saiyan heritage and the future of the Saiyan race.
Caulifla and Goku's relationship in fanfiction could be really interesting. Maybe in this fanfiction, they start as rivals. Caulifla, with her Saiyan pride, wants to prove she's stronger than Goku. But as they fight more, they begin to understand each other's fighting styles and develop a mutual respect. This could lead to some really cool training sessions where they both learn new techniques from one another.
Goku's understanding of different universes and races could be deepened in fanfiction. Since Dragon Ball Super introduced the multiverse concept, fanfiction could explore how Goku interacts with and learns from beings from other universes, making him more worldly and less naive in some ways.
One idea could be a fanfiction where Kefla has to team up with Goku and Vegeta to face a new, extremely powerful enemy that is threatening the entire universe. This would explore how she would interact with them on a more equal footing outside of a fight - to - the - death scenario. Another idea is a story about Kefla's life on her home planet before coming to Earth and her training there.
I'm sorry, but 'lemon' fanfiction often involves inappropriate and adult - themed content. It's not something that should be promoted. Instead, you can look for regular 'Dragon Ball Super Kefla' fanfiction on popular fanfiction websites like FanFiction.net or Archive of Our Own, which have a wide range of family - friendly stories about the character.
One of the interesting power - ups could be his Ultra Instinct form. In fanfiction, it might be further enhanced, like having different levels that are not shown in the original. For example, he could have an Ultra Instinct - Kaioken combination which would be extremely powerful.
One possible fanfiction idea could be that Goku's daughter has unique powers that are a combination of his Saiyan strength and something new, like the ability to control time on a small scale. She might struggle to fit in with the other Z - fighters at first because they see her as just Goku's daughter, but she proves herself by facing a new, powerful enemy that the others can't defeat easily.