The relationship between the last human and the environment is often explored. The world has changed, and they have to adapt to it. There could be themes of the last human's connection to nature or how they interact with the remnants of human civilization. And sometimes, there's a theme of discovery, like the last human finding something unexpected that gives them a new hope or changes their perspective on the situation.
Survival is a very common theme. Since the main character is the last human, they have to find ways to stay alive in a world that is either empty or full of danger. For example, in many of these fanfics, Harry has to figure out how to get food and shelter without the support of the wizarding community as it once was.
One common theme is friendship. The relationship between the human and Senketsu often develops into a strong bond of friendship. Another theme is growth. Both the human and Senketsu usually grow as characters throughout the story, learning from each other. Also, the theme of facing challenges together is quite prevalent as they encounter various obstacles in their adventures.
Self - discovery is another theme. Through their relationship with Toothless, the human often discovers new things about themselves, like hidden courage or a new perspective on the world. And for Toothless, his interactions with the human can also lead to self - discovery, perhaps learning about the value of a different kind of relationship compared to those with other dragons.
One common theme is friendship. Like in many stories, the dragon and the human start as strangers but gradually become friends and rely on each other. For example, in 'A Dragon's Friend', the human helps the dragon when it's trapped and in return the dragon protects the human from danger.
Often, there's a theme of hidden powers or abilities. Even as a human, Jasper might have some remnants of her previous self. This could be in the form of enhanced senses or a special intuition. Fanfiction writers like to explore how she uses these to her advantage or how she tries to hide them from others in the human world.
Power growth is a very common theme. Writers often explore how the characters can become stronger in different ways compared to the original story. Another common theme is relationship development, like the romantic relationships between characters.
Another theme is cooperation. Sometimes, they realize that by working together, they can achieve greater things. In some stories, they join forces to fight against a common enemy like an ancient evil or a powerful dragon. This theme shows how they can overcome their differences and use each other's strengths. It often involves a lot of character development as they learn to trust one another.
A common theme is friendship. The human and the rabbit often become friends in these stories, like when the rabbit is a stray and the human takes it in. Another theme could be adventure. They might go on a journey through a forest or an unknown land together.
Love is a very common theme. Usually, a mermaid and a human fall in love despite their differences. Another theme is the struggle between two different worlds. The mermaid belongs to the underwater world and the human to the land world, and they have to find a way to be together.
Survival is a big theme. In these fanfictions, humans have to figure out how to survive in a world dominated by dinosaurs. They need to find food, shelter, and avoid being eaten. The theme of friendship also appears. Sometimes a human befriends a dinosaur, like in the story where a lonely boy forms a bond with a gentle herbivore dinosaur. Additionally, the idea of time - travel is common. It allows for the mixing of different eras, with humans from the present going back to the dinosaur age or vice versa.