Sure. There are quite a few. You could look on platforms dedicated to fanfiction. In these stories, Godzilla and Mothra's relationship can be explored in many ways. It might be a romantic love, or a deep friendship. Some stories might even give them new powers or abilities in the context of their relationship.
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.
Sure. 'The Bond of Mothra and Godzilla' is a great one. It focuses on their unique relationship in a world full of chaos. They have to team up against a common enemy and during the process, their bond deepens.
The next movie that wasn't the 2014 version of Godzilla was Godzilla 2: King of the Monsters. However, Godzilla versus King Kong was not a movie plot but a comic book or novel plot.
No, the 1954 Godzilla movie was one of Godzilla's earliest works, but it was not the earliest. The name Godzilla first appeared in a Japanese manga of the same name in 1942. Before that, there were other forms of Godzilla's image, such as appearing in news reports, posters, and advertisements.
One common theme is the struggle between her kaiju nature and her human form. For example, in many stories, she has to deal with emotions and limitations that are new to her in human form.
Another theme is the idea of redemption. Sometimes in fanfiction, Gigan is given a chance to change his ways through his encounters with Mothra. It's an interesting way to explore his character. And also, the theme of cooperation despite differences is quite popular. Given their very different natures, seeing them work together is a fascinating concept in many of these fanfictions.
One common theme is the battle between technology (Mechagodzilla) and nature (Mothra). It often explores how these two very different forces interact and conflict.