A possible fanfiction could involve a shapeshifter who is actually an alien sent to study the Avengers. The shapeshifter takes on the forms of different Avengers to understand their powers and personalities better. However, they get caught up in a battle against a common enemy and end up becoming a true part of the team, using their unique shape - shifting abilities to outwit the foe.
In a shapeshifter Avengers fanfiction, the shapeshifter could be a long - lost relative of one of the Avengers. They have been living in hiding due to their shape - shifting abilities being feared in their home world. When they come to Earth and meet the Avengers, they initially struggle to fit in. But with time, they learn to control their powers and become an invaluable asset to the team, especially in situations where stealth and deception are required.
One idea could be a shapeshifter who infiltrates the Avengers under the guise of a new recruit. They start causing chaos within the team by spreading false information and creating mistrust among the members. But as the story unfolds, the shapeshifter has a change of heart and decides to use their powers for good instead, helping the Avengers defeat a greater threat.
A great way to create a compelling shapeshifter character is to make them an outcast. In the context of an Avengers fanfiction, the shapeshifter could have been rejected by society because of their power. This would give them a complex personality, as they might be both resentful and desperate for acceptance. Also, let their shape - shifting ability reflect their emotions. When they're angry, they might involuntarily shift into a more menacing form. This adds depth to the character.
How about a story where a shapeshifter family moves into a new town? The family members can transform into different things to adapt to the new environment and help the local people. For instance, the father might change into a strong bear - like form to move heavy objects during a community building project, while the mother could transform into a gentle dolphin - like creature to teach kids about the ocean in a local school.
Another option is a crossover with a different anime world, like Naruto. GT Goku could end up in the Hidden Leaf Village. The shinobi would be amazed by his power. Goku, being Goku, would be interested in learning their ninja techniques. They could team up against a common enemy that somehow has the ability to use both chakra and ki, creating a unique and exciting battle scenario.
One idea could be to focus on the characters' different abilities. Blade's vampire - hunting skills and the unique powers of the Underworld vampires could create some intense fight scenes. For example, Blade could team up with Selene from Underworld to take on a new, more powerful vampire threat that combines the worst aspects of both their worlds.
A more complex scenario could involve a group of witches who are at war in their own realm. They decide to bring some of the powerful Naruto characters into their world to fight on their behalf. Naruto and his friends would have to adapt to the strange magic - filled environment and the political intrigue of the witches' war.
One idea could be a crossover with the 'Lord of the Rings' universe. The Soul of Cinder could be a powerful entity that somehow ends up in Middle - earth. Maybe it's mistaken for a dark lord by some and has to prove its true nature. Another option is a crossover with 'Final Fantasy'. The Soul of Cinder's abilities could be translated into the magic and combat system of 'Final Fantasy', creating some really interesting battles.
One idea could be a pokemon shapeshifter that is trying to hide its true form in a human - dominated city. It has to constantly adapt and learn human behaviors to avoid detection.
One idea could be that Harry uses his shapeshifting ability to spy on the Death Eaters unnoticed. He could transform into a small creature like a mouse and infiltrate their meetings.
One idea could be a dragon shapeshifter who is forced to hide in human form in a modern city. They have to constantly struggle to keep their true identity a secret while also being drawn to other magical beings in the city. Another plot could involve a dragon shapeshifter falling in love with a human, and having to decide whether to reveal their true form or not. Or perhaps a story where a dragon shapeshifter is on a quest to find a lost magical artifact that is crucial for the survival of their dragon clan.
One plot idea could be Percy using his shapeshifting ability to infiltrate the lair of a powerful enemy. He could transform into a small animal like a mouse to get past defenses and then change into a more formidable form to fight. Another could be Percy struggling to control his shapeshifting, accidentally changing forms at inconvenient times, like during a school exam or a tense conversation with his friends.