Well, the theme of adaptation is quite prevalent. Characters from Gravity Falls have to adapt to the violent and dangerous world of Gears of War and vice versa. And there's also the theme of heroism. Whether it's Dipper and Mabel in Gravity Falls or Marcus Fenix in Gears of War, the characters are often put in situations where they have to be heroic to overcome challenges. There are also often elements of family and friendship, as both original works have strong relationships within the casts that are explored in the fanfiction.
Sure. One great Gravity Falls and Gears of War fanfic is 'The Crossover Adventure'. It combines the mystery elements of Gravity Falls with the intense combat of Gears of War in a really unique way. Another one is 'Mystery in the War-Torn World' which has an interesting plot where the characters from Gravity Falls find themselves in the Gears of War universe and have to adapt to survive.
One common theme is rebuilding. After the destruction of the war, the characters often have to rebuild the town, their relationships, and their lives. Another theme is healing, both physical and emotional. For instance, characters might be dealing with injuries or trauma from the war.
Another theme might be the mystery aspect related to the pregnancy. In Gravity Falls, there are always strange things going on. So, the pregnancy could be linked to some sort of supernatural or mysterious event. Maybe the baby has some special powers or there are some strange occurrences during the pregnancy that tie into the overall mystery of Gravity Falls.
Adventure is also a big theme. Given the nature of Gravity Falls, fanfictions often send Dipper and Pacifica on various adventures. They might be exploring a new part of the forest, or uncovering a mystery that has been hidden for ages.
Friendship is a common theme. Even in a harem - like situation, the characters often start with a basis of friendship. For example, Dipper might be friends with all the potential 'harem' members before any romantic feelings start to develop.
One common theme is the clash of different worlds. Naruto's ninja world is so different from Gravity Falls' spooky and mysterious world. So, when they combine, there's often a lot of confusion and discovery for the characters.
One common theme is self - discovery. Since Dipper is now female in these fictions, she often has to navigate a different set of social and personal experiences compared to the male version. For example, she might face different types of relationships with other characters like Mabel or the townsfolk.
One common theme is mystery. Since Gravity Falls itself is full of mysteries, fanfictions often have the reader character getting involved in solving those mysteries, like the secrets of the strange creatures or the hidden meanings behind the town's oddities.
A common theme is power and its corrupting influence. Since Bill is a very powerful character, in female Bill fanfiction, it often explores how she wields that power, whether for good or bad. For example, some stories might show her initially using her power for self - gain but then having a change of heart.
Another common theme is friendship. The main characters in both shows are young and form strong bonds with their friends. In crossover fanfiction, you'll often see the characters from Hilda befriending the characters from Gravity Falls. They might rely on each other's unique skills and knowledge to get through various challenges, like when Hilda uses her wilderness skills and Dipper uses his mystery - solving abilities to face a common threat.