Well, often you'll find themes like cultural exchange. Since the Ninetails is a mythical being, there could be elements of its own culture being shared with the human. Another theme could be power dynamics, with the Ninetails potentially having more power and how that plays out in the relationship.
Some common themes could be the exploration of a unique relationship. It might involve the Ninetails' otherworldly charm and how it affects the human. Maybe themes of loyalty and sacrifice as the relationship between the two develops.
First, create a strong conflict. For example, the differences between the Ninetails' world and the human world could lead to problems. Then, build the relationship gradually. Don't rush it.
One common theme is adventure. Since they are based on the How to Train Your Dragon world, they often go on quests together.
A prevalent theme is also acceptance. Naruto has to accept these two unique entities into his life, and they in turn have to accept him and each other. It's about how different beings from different backgrounds can come together. And there's often the theme of adventure as they go on various quests or face threats in the Naruto world.
One common theme is friendship. Since Hiccup and Toothless have a strong bond in the original, this is often explored in a different way when Hiccup is female and Toothless is human. Another theme could be adventure. They might go on quests together, just like in the original but with a different dynamic.
One common theme is friendship. Despite their differences, kaiju and humans often form bonds of friendship in these fanfictions. Another is co - existence, exploring how they can live together in the same world. And there's also the theme of discovery, like a human discovering something new about kaiju or vice versa.
One common theme is friendship. The human and Reshiram often start as strangers but gradually become friends, relying on each other in various situations. Another theme is adventure. They usually embark on some sort of journey, whether it's to save a region or to discover something new about the Pokémon world.
A frequent theme is the forbidden nature of their relationship. In most lore, wendigos are dangerous and evil, so a relationship with a human is something that goes against the natural order. Also, survival is a theme. The human may be in a situation where they need to survive in the wendigo's territory, and that's how their relationship starts. And there's the theme of transformation, where either the wendigo or the human changes because of their relationship.
A common theme is the clash of two different worlds. Kurama being a demon and the human coming from a completely different realm. Another theme is acceptance. The human has to accept Kurama's true nature and Kurama has to understand human emotions and values.
One common theme is the underdog story. The human is often the underdog compared to the elite, and through their interactions, they grow and overcome challenges. For example, a regular student working with an elite scholar.
Nature and spirituality are common themes as well. The wolf is often associated with nature and spiritual elements in different cultures. In human x wolf fanfiction, the presence of the wolf can bring the human closer to nature and a deeper understanding of spiritual forces. For instance, the wolf might lead the human to a sacred place in the forest, where they have a profound spiritual experience.