In the fanfic, perhaps Goku's transformation into a girl is the result of a magical spell. As a girl, she might start to see the world from a different perspective. She could be more in touch with her emotions and this could either enhance or hinder her fighting abilities. For instance, she might be more empathetic towards her enemies, which could lead to some interesting moral dilemmas during fights. Her training regime might also change as she adapts to her new body.
Krillin would probably be one of the first to be accepting. He's always been Goku's friend and would likely see Goku's inner strength regardless of the physical form. He might even joke about it a bit at first. Vegeta, on the other hand, would be initially shocked and perhaps a bit dismissive. But as he sees Goku's power in the new form, he would gradually come to respect it. Gohan would be very curious and would want to know how this transformation happened and what it means for their future battles.
Well, one possible plot could be that Goku, as a girl, has to face different challenges in the martial arts world. Maybe the other fighters underestimate her at first, but she quickly proves them wrong with her incredible strength and skills. She might also have to deal with new emotions and how others perceive her femininity in the context of being a powerful fighter.
The character development could be interesting. Goku, now a girl, would have to adapt to different social expectations. She might become more empathetic as she experiences some of the things that female characters in the Dragon Ball universe face. For example, she could be more in tune with the emotional needs of her friends and family.
First, you need to establish the reason for the transformation. It could be a magical spell gone wrong, or some kind of strange dragon - related phenomenon. Then, focus on how Hiccup adjusts to her new body. She'll have to deal with different physical abilities and limitations. For example, she might be physically not as strong as before, but more agile in some ways.
A fanfic could explore how Hiccup's transformation into a girl affects his friendships. Astrid might react in a complex way. At first, she could be jealous or confused, but then they could form a stronger bond. Also, Hiccup's father, Stoick, might have a hard time adjusting to his son becoming a daughter, which could add a lot of emotional depth to the story.
One possible scenario in this fanfic could be that Tony Stark, through some sort of magic or scientific experiment gone wrong, turns into a girl. This could lead to a whole new set of adventures and character developments. For example, his relationships with other characters like Steve Rogers (Stony) would be completely different. He might have to face new challenges in a different physical form, such as how society and his friends would accept him. Also, his own self - perception would change, and he'd have to re - evaluate his identity.
Goku's fighting style might become more fluid. Female characters are often depicted as having more grace in movement, so Goku as a girl could incorporate some elegant dodges and strikes into her already powerful combat techniques.
Well, in a 'freed turns into a girl' fanfic, the plot might start with an experiment gone wrong. Freed was perhaps trying to enhance his magic power and something in the experiment caused his physical form to change to that of a girl. He would have to deal with the reactions of his guildmates. Some might tease him, while others would be more understanding. And he would also face challenges like how to adapt to the new body's physical limitations while still being able to participate in guild activities.