Well, often there's the theme of mutual discovery. The male human discovers the dragon's world, which is full of magic and mystery that he's never known. And the female dragon, in turn, gets to know about human emotions and culture more closely. Also, a theme of protection might be present, where the dragon protects the human from various threats, creating a bond between them.
The theme of transformation can also be common. Sometimes the human might gain some dragon - like abilities or the dragon might take on more human qualities as they interact. Another theme is the struggle against society's norms. Since their relationship is not typical, they often have to fight against the expectations and prejudices of their respective species' communities. This adds a layer of drama and conflict to the fanfics.
One common theme is the idea of acceptance. The male human has to accept the dragon anthro's different nature, like her powers and appearance. For example, in many stories, the human is initially afraid but then learns to embrace her dragon - like qualities.
Common themes often revolve around loyalty. Glaceon could be fiercely loyal to the human it befriends, and the human could also show unwavering loyalty. There's also the theme of adaptation. The human has to adapt to the world of Pokémon where Glaceon lives, and Glaceon might have to adapt to human ways. Additionally, there could be a theme of cooperation. They work together to achieve a common goal, whether it's saving a Pokémon in trouble or finding a rare item in the Pokémon world.
Transformation is also a common theme. Sometimes the male human may be in danger of being turned into a werewolf, or the female werewolf may try to suppress her werewolf side for the sake of the relationship. Additionally, the idea of loyalty is often explored. The female werewolf's loyalty to her pack and how that conflicts or aligns with her loyalty to the male human, and the male human's loyalty to the female werewolf in the face of potential danger from other humans or werewolves.
Love and acceptance is also a prevalent theme. The relationship between the female dragon and male human may face many challenges, not just from the difference in species but also from the reactions of others in their respective worlds. Overcoming these obstacles to find love and acceptance is a common plot point in such fanfictions.
Common themes include transformation. The male human may be changed by his relationship with the female dragon, either in his personality or his physical abilities. The female dragon might also experience a form of transformation, perhaps in her view of humans. Love against all odds is also a big theme. They are from different species, and there may be many obstacles in their way, but they still fall in love. And the theme of mutual understanding is key. They need to understand each other's needs, wants and limitations in order to make their relationship work.
One common theme is friendship. The human and the dragon start off as strangers, perhaps even wary of each other at first. But as they interact more, they realize they can help each other out. Another theme is adventure. They might embark on a journey together to find a lost treasure or to defeat a common enemy. Also, the theme of mutual respect often shows up, where the human respects the dragon's power and the dragon respects the human's intelligence or courage.
Friendship is also a wonderful theme. A story could be about how a male human, who is initially scared of Pokemon, meets a female Pokemon and over time, they become the best of friends. They learn from each other, like the human teaching the Pokemon about human culture and the Pokemon showing the human the secrets of the Pokemon world.
Often, there are themes of self - discovery. As they interact, Roman and Virgil may learn more about themselves. In these fanfics, their individual insecurities might be explored, like Roman's need for validation and Virgil's fear of being rejected, which then ties into how their relationship evolves.
Some 'female nergigante x human' fanfics may also have a theme of transformation. Maybe the human character is influenced by the nergigante in some way, either physically or mentally, and this transformation becomes a central part of the story. It could be a slow process that changes the human's perspective on life and the world around them.