There's a plotline where Tails' transformation into a girl is a side - effect of a time - travel accident. She ends up in a different timeline where she's a girl, and she has to figure out how to get back to her original form and timeline. This one is interesting because it plays with the concepts of time and alternate realities along with the transformation.
Some fanfictions have a plot where Tails is turned into a girl by an alien race for some kind of experiment. This leads to her being in a strange new body and having to interact with the aliens while her friends are trying to rescue her. It's a really cool take on the idea as it combines the transformation with an outer - space adventure.
A unique plotline could be that Tails is turned into a girl as part of a prophecy. In this story, she has to fulfill certain tasks in her new form to save the Sonic world. It adds an element of destiny and adventure to the whole transformation concept.
One interesting 'naruto gets fox tails' fanfiction could be where Naruto gains the fox tails as a new form of power. This might change the way he battles and interacts with other characters in the Naruto universe. For example, he could use the tails for enhanced speed and strength in combat, or for new jutsu combinations that are unique to this form.
Often, the themes include adaptation. Stiles has to adapt to his new fox body, which might have different physical abilities and limitations. There's also the theme of mystery, like trying to find out how he got turned into a fox and how to reverse it. And of course, there's the theme of relationships. His relationships with his friends, family, and love interests will all be affected by this transformation.
One interesting plotline could be Natsu trying to adjust to the new physical form while still having the same adventurous spirit. For example, Natsu might initially struggle with wearing different types of clothes that are more suitable for a female body. Another plotline could be how Natsu's friends react. Some friends might be shocked at first, but then quickly accept and help Natsu through this strange transformation. There could also be a plotline where Natsu discovers new abilities or sensitivities that come with being in a female form.
The theme of empowerment is quite common. Despite the challenges of being turned into a girl, Bilbo often shows great strength and intelligence. These fanfictions usually depict her as being able to overcome difficulties and prove herself just as capable as she was as a male. This can be inspiring as it shows that gender doesn't necessarily limit one's abilities in the context of the story.
One possible plotline could be that Tails is killed by a powerful enemy during a battle to protect his friends. Maybe a new, extremely strong villain emerges and Tails sacrifices himself to buy Sonic and the others time to escape. Another could be that there is some sort of accident in Tails' workshop while he is working on a dangerous experiment, leading to his untimely death. It could also be that in a dark alternate universe, Tails is targeted and assassinated by an evil organization that wants to disrupt the balance of power in the world he lives in.
One possible 'tails the fox sick' fanfiction could be about Tails getting a strange illness that makes him lose his ability to fly temporarily. The other characters in the Sonic universe might then have to come together to help him find a cure.
One interesting 'Naruto Gets Nine Tails' fanfiction could be where Naruto has an even deeper connection with the Nine - Tails than in the original series. For example, he can communicate with it telepathically without any chakra interference. Another one might be a fanfiction where Naruto uses the Nine - Tails' power in creative ways to solve problems that the original Naruto couldn't. Maybe he uses it to heal instead of just for combat.
One popular one might be 'Tails' New Form' where the transformation is a result of a magical mishap. It delves into how Tails, now as a girl, adjusts to the new body and the reactions of her friends in the Sonic universe. It's a really interesting take on the character and has some great character development moments.
One possible plotline could be Naruto having to adapt to his new fox form and learning how to use its unique abilities. For example, he might discover that in fox form he has enhanced speed and stealth, and he has to figure out how to incorporate these into his fighting style.
Well, in some fanfictions, Harry's contacts might be enchanted to show the true nature of people. So, when he looks at someone, he can see if they are good or bad. For example, if a Death Eater is in disguise, the contacts would reveal their true identity. This adds an interesting layer to the story as Harry can now be more aware of who he can trust.