Well, a typical theme in such fanfics is the bridging of different worlds or statuses. Celestia is royalty and has a lot of responsibilities, while Rainbow Dash is more of a free - spirited athlete. Fanfics might explore how they come to understand each other's worlds. Another common theme is the idea of unexpected relationships. It's not a pairing that is immediately obvious in the My Little Pony canon, so fanfics often play with the idea of how such a relationship could develop, whether it's a slow - burn romance or a strong bond of a different kind.
One common theme could be mentorship. Celestia is an older and wiser character, so she might mentor Rainbow Dash in some way. Another theme could be friendship that develops into something more special over time.
Another theme is adventure. They could go on an adventure together, perhaps to a new and mysterious part of Equestria. During this adventure, they learn more about each other and their own capabilities. This can lead to a lot of character development for both Rainbow Dash and Twilight.
One common theme is friendship. Since Rainbow Dash is a character known for her loyalty, many fanfics explore how she forms a strong bond of friendship with the reader. It could be through shared adventures or helping each other out in tough situations.
One common theme is mentorship. Rainbow Dash can be seen as a role model for Scootaloo in many fanfics.
Another theme is the idea of friendship turning into love. They start as friends, and through shared experiences and understanding, their relationship deepens romantically. For example, in many fanfics, a joint adventure or a difficult situation they face together sparks new feelings.
I'm not sure of specific 'rainbow dash x celestia fanfic' titles offhand. But you can try searching on fanfic platforms like Fimfiction. There are often a lot of great fan - created stories there that might include this pairing.
Friendship is also a big theme. Since she's part of the Mane Six, fanfics often explore how her friendships develop and are maintained. It could be about how she helps a friend in need or how her friends support her during a difficult time.
One common theme is friendship. Given that they are both characters from the MLP universe which highly values friendship, many fanfics explore how their friendship develops. Another theme is competition, as both are pegasi and might compete in flying races or other aerial challenges in the fanfics.
Another theme is self - discovery. As they interact with each other, they often learn more about themselves. For instance, Rainbow Dash might discover a new aspect of her courage or Sunset Shimmer might find a different way to use her magic. These fics use their relationship to explore the characters' internal growth, which makes the stories more meaningful and engaging.
A sense of discovery is also prevalent. The reader discovers new aspects of Equestria, new magical elements, and also discovers more about themselves and their relationship with Rainbow Dash. This can include learning about new flying techniques if the reader is also a pegasus in the story, or just exploring new parts of the land together.
One common theme is adventure. They might go on some exciting quests together as humans. Another theme could be friendship evolving into love. Since they are often friends in the original context, the fanfics may explore how that relationship deepens in a human setting.