Well, a common theme is adaptation. Characters need to adapt to their new shrunken size. This includes finding new ways to communicate, move around, and defend themselves. Another important theme is the discovery of hidden powers or abilities. Sometimes, being shrunk reveals latent powers within the characters. And of course, there's the theme of the fight against the odds. The shrunken characters are often at a great disadvantage, but they still strive to overcome the supernatural threats that surround them.
One common theme is the struggle for survival. When characters are shrunk in a supernatural setting, they have to find ways to stay alive. Another theme is the exploration of the now - giant world around them. They might discover new things about the supernatural realm that they couldn't see before.
The theme of isolation is also prevalent. Being shrunk can make a girl feel very alone in a world that doesn't understand her situation. However, this isolation can also lead to growth as she learns to rely on herself. Additionally, the idea of finding a way back to normal size is a constant theme. It drives the plot in many shrinking girl fanfictions as she searches for a cure or a magic solution to reverse her condition.
In 'supernatural fanfiction', a frequent theme is the alternate universes. Writers like to imagine different versions of the 'Supernatural' world, where things happened differently. Romance is also a big theme, whether it's between the main characters or new characters introduced in the fanfic. Also, the origin stories of the supernatural beings are often explored, giving more background and depth to the existing lore.
One common theme is the feeling of isolation. As the character shrinks, they become more and more separated from the normal world. For example, in 'The Shrinking Man', the protagonist feels alone as he can no longer interact with things in the same way as before.
One common theme is power. Different bloodlines have different powers, and often there are power struggles or characters trying to control or harness their own powers. Another theme is identity. Characters are often trying to figure out who they are based on their bloodline heritage.
One common theme is the exploration of unknown powers. Sasuke and Naruto often find themselves with new, supernatural abilities that they need to figure out. Another theme is friendship in the face of danger. They have to rely on each other in the dangerous supernatural situations.
A common theme is the insignificance of humanity. In Cthulhu stories, humans are often just tiny specks in the face of the vast and powerful cosmic entities. Another theme is the corruption of the mind. Characters are often driven mad by the mere knowledge or proximity of Cthulhu and his ilk.
One common theme is the clash between military order and supernatural chaos. The soldier has to use his military training to deal with unpredictable supernatural situations.
One common theme could be the vulnerability of the characters. Diapers can symbolize a state of helplessness or a new level of caretaking. For example, if a character is injured or cursed, it might lead to a situation where they need diaper - like care, which adds an interesting dynamic to the relationships between characters in the Supernatural universe.
One common theme is redemption. Since Adam was sort of left behind in the show, many fanfictions focus on him redeeming himself or finding his purpose. Another theme is family. Adam trying to fit into the Winchester family dynamic is often explored.
Identity is another big theme. Nephilim are a unique blend of human and angel. Fanfictions often show them trying to figure out where they belong. Are they more human or more angel? And how do they fit into the world of the supernatural which has its own rules and hierarchies? This exploration of identity can be really interesting and complex.