Since I haven't actually read such fanfiction, it's hard to say for sure. But perhaps themes could include the challenges of a pregnant kaiju, how the other monsters in the Godzilla universe react, or the idea of a new kind of monster being born.
Well, it could potentially explore the concept of new life in a very different and fantastical context. There might be themes around protection, as Godzilla would need to safeguard its unborn. Also, the relationship between Godzilla and other characters in the fanfiction might change due to the pregnancy. For example, if there are human characters, they might have different reactions and interactions with a pregnant Godzilla. It could also touch on the idea of the future of the Godzilla species if a new offspring is on the way.
A prevalent theme is the power dynamic between them. Sometimes the male Godzilla is depicted as the stronger one, but in some fanfictions like 'The Equal Partners', they are shown as equals in terms of strength and intelligence. Also, the theme of discovery is common. For example, in 'The Discovery of a New Bond', they discover new aspects of their relationship and their own abilities as they face various challenges together. Love and loyalty also play a big part in many of these stories, especially in ones that focus on their relationship on a more emotional level.
One common theme is protection. Godzilla is often depicted as protecting baby Godzilla from various threats, be it other monsters or human interference. Another theme is growth, showing baby Godzilla's development into a more powerful creature over time.
One common theme is power. Godzilla is extremely powerful, and in the DxD universe which also has powerful characters, exploring how his power compares and interacts is a big theme.
Possible themes could include the reaction of the other kaiju (monsters) to this strange event. It could also focus on the relationship between Godzilla and SpaceGodzilla in a more domestic or family - oriented context, which is a huge contrast to their usual roles of fighting. Additionally, it might touch on how the pregnancy changes Godzilla's role in the ecosystem of the kaiju world, and how other creatures respond to this new situation.
One common theme is the epic battles. Fans often write about Godzilla Earth facing off against other powerful monsters in intense combat.
Another theme is sacrifice. Godzilla is a powerful being, and in these fanfictions, he may have to sacrifice his power or safety for the sake of his love. It adds a layer of depth to the story as he has to make difficult choices between his role as a protector and his new - found love.
One common theme is cooperation. Since they are both powerful creatures, many fanfictions explore how they can work together. Another theme is the balance of power. Writers often play with the idea of who is stronger and how that affects their relationship.
The theme of the unknown also runs through these fanfictions. Godzilla is an otherworldly creature to the people of Westeros. His motives, abilities, and even his very existence are a mystery. Fanfic writers often explore how the characters in Game of Thrones react to this unknown entity, whether they are filled with fear, curiosity, or a combination of both.
One common theme is survival. Since Godzilla is such a powerful and often dangerous creature, the humans in these fanfictions are usually focused on just staying alive in his presence. For example, in many stories, they have to find ways to avoid being crushed or caught in the crossfire of Godzilla's battles.
One common theme is the power dynamic between them. Since Godzilla is so big and strong and Mothra has her own unique abilities. Another theme could be sacrifice, like one sacrificing for the other in a dangerous situation.