In the fanfic, Link could be magically changed into a girl due to a wish made by an innocent character. Link then has to find a way to reverse the transformation while still dealing with the challenges of the world. He might face discrimination or different expectations from others in his new form, which could add depth to the story.
One idea could be that Link is cursed by an evil sorcerer to turn into a dragon. In the fanfiction, he might initially struggle with his new form, not understanding how to fly or use his dragon powers. As the story progresses, he could discover that his dragon form has unique abilities like breathing fire to defeat enemies he couldn't before. He might also have to find a way to break the curse while still in dragon form, perhaps by finding a magical artifact or by performing a heroic deed.
Next, consider how Link will react to becoming a girl. Will he be confused, angry, or curious? His emotions and internal struggle can be a big part of the fanfic. You can also think about how the other characters in the Zelda universe will react to his new form. Some might be accepting, while others could be more hostile or confused.
One idea could be that Naruto's greed is for power. He might see all the strong shinobi in the Hidden Leaf and start to envy their abilities, so he becomes greedy for more power. He could start seeking out forbidden jutsu or training methods that are considered dangerous.
One idea could be that Sonic, through some magical or scientific accident, is transformed into a baby girl. In the fanfiction, his friends might initially be very confused. For example, Tails could be trying to figure out how to reverse the process while also taking care of Sonic in his new form. Sonic, as a baby girl, could have different abilities or limitations. Maybe she can't run as fast as before but discovers new powers related to cuteness or charm that help the gang in unexpected ways.
One idea could be that Ash uses his unique battle style which he has developed over his journey to create a really challenging gym. He might include Pokémon from all the regions he has visited in his gym battles, making it a diverse and exciting experience for trainers. For example, he could have Pikachu lead the charge as always, but also include some of his less common Pokémon like Heracross or Gliscor.
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.
In a fanfiction where Naruto becomes a cyborg, his appearance would likely change. He could have mechanical limbs that are sleek and powerful. His ninja way might also be affected. He might start to see himself as more of a weapon, but then realize that his humanity is still what makes him strong. He could use his new cyborg abilities to protect the village in ways he never could before.
Perhaps in this fanfiction, Draco's transformation into a female could be the result of a spell gone wrong. As a female, she then has to navigate her relationships differently. Her friendship with Blaise or enmity with Harry could take on new dimensions. She might find that she is treated differently by her Slytherin peers, and this could be a source of both frustration and self - discovery.
In this fanfiction, Naruto might be recruited by a secret organization within Konoha to be a spy. He could use his unique ability to sense emotions to tell when people are lying. For example, when he's at a meeting of enemy shinobi, he can quickly pick out the liars and get closer to the truth. Also, his experience with befriending people could help him gain the trust of those he's spying on.
One idea could be that Naruto discovers a strange portal that transports him to the Pokemon world. Since he has his ninja skills, he quickly adapts. He might start by befriending Pikachu, as it's one of the most iconic Pokemon. His goal could be to become a Pokemon master, using his determination from being a ninja.