A fanfic could focus on Female Trunks' relationships. Maybe she has a special friendship with Bulma that is different from the original male Trunks' relationship with his mother. She could also have romantic interests that are shaped by her being a Saiyan and her place in the DBZ universe. It could explore how she balances her Saiyan warrior side with her more emotional and relationship - oriented side.
Well, you could do a time - travel based crossover fanfiction. Have a legendary super saiyan like Vegeta travel back in time to a different era in the Dragon Ball Z universe. He could meet his younger self and together they could face a new threat that was previously unknown. Or, a crossover with a video game world. Picture the legendary super saiyan Trunks entering the world of Final Fantasy and having to go on a quest there.
Well, it would be an amazing transformation. He'd probably gain incredible power. His magic could be enhanced even more, and he might be able to defeat Voldemort with just a single blast. His physical abilities would also skyrocket, allowing him to move at super - fast speeds and endure more damage in battles.
He becomes more resourceful. In his own time, he's used to a certain set of circumstances. But during time travel, he has to adapt quickly to new situations and find ways to use the resources available in the past. For example, he might have to figure out how to use different senzu beans or power - up techniques that are new to him.
Definitely characters from other shonen anime. For instance, Luffy from One Piece. His rubbery abilities and carefree attitude would contrast well with the serious and powerful super saiyans. Another good character could be Ichigo from Bleach. His sword - fighting skills and unique power could make for an interesting interaction with the super saiyans' ki - based attacks.
It could be his father, Vegeta. Vegeta is known for his strict training methods and high expectations. If Trunks fails to meet those, Vegeta might punish him to make him stronger.
One possible plot could be Future Trunks traveling back in time to prevent a new threat that he discovers in his own time. For example, a powerful and unknown enemy is about to emerge in his future, and he goes back to enlist the help of Goku and the others before it's too late. Another plot could involve Trunks accidentally changing something in the past that has unforeseen consequences in his future, like messing with the timeline of a certain character's power - up, which then leads to a whole new set of challenges when he returns to his own time.
Yes, there are quite a few out there. Some explore their relationship in unique ways, like Trunks protecting Pan during a new threat in the Dragon Ball universe. You can find them on various fanfiction websites.