One key element is Luna's character. Since she's a complex character with a past of being Nightmare Moon, fanfics often explore her redemption and her relationship with the other ponies. Another element is the magical world of Equestria. Fanfics use this setting to create unique stories around Luna, like her connection to the night sky and moon magic.
Themes of betrayal can be common. If Luna was betrayed by someone she trusted, it would be a very sad situation. This could be a pony she thought was her friend or an ally. The resulting sadness could lead to her withdrawing from others and becoming even more melancholy as she tries to deal with the pain of the betrayal.
A fanfic titled 'Luna's Redemption in Celestia's Eyes' is quite interesting. It focuses on Luna's journey towards redemption from Celestia's perspective. It shows how Celestia has always believed in Luna, even during her darkest times. The story is filled with emotional moments that really tug at the heartstrings.
Fanfics about Luna and Celestia also allow for a lot of world - building. Since they are such important figures in the MLP universe, their fanfics can introduce new elements to Equestria. It could be a new type of magic that only they know about or a hidden part of Equestria that is connected to their origin. This not only adds depth to their characters but also to the overall MLP lore.
Some fanfics might explore the idea of Luna and Celestia having different opinions on how to rule Equestria. Celestia might be more about harmony and peace through sunlight and positive energy, while Luna could believe that the night also has its own power and should be more emphasized. This can lead to interesting conflicts and resolutions within the fanfic.
Another theme is friendship. Even as a baby, Luna is shown forming bonds with other ponies or characters, like how she might interact with her sister Celestia in a more innocent and playful way. And these interactions help shape her future relationships. For example, in some fanfics, her early experiences with friendship teach her important values that she carries into her later life.
A common theme is friendship. Despite their different personalities, they often end up becoming friends in fanfics. Another theme is magic. Since both are associated with magic in the My Little Pony world, their magical abilities are often explored. For example, they might combine their magic to defeat a common enemy.
One common theme is redemption. Since Luna has had a troubled past with her banishment and all, many fanfics focus on her trying to redeem herself in the eyes of the other ponies. For example, she might be trying to make up for the bad dreams she caused in the past.
One possible plotline could be that Luna sacrifices herself to save Equestria from a powerful and ancient evil. She might use all of her magic and strength to defeat the foe, but in the process, it drains her life force completely.
Well, in a fanfic, Princess Luna's daughter could be a very interesting character. She might have a special bond with Twilight Sparkle, learning from her about friendship and magic. Her appearance could be a blend of Luna's ethereal beauty and some new elements. Maybe she has a mane that shimmers like the night sky with little twinkling stars in it. And her cutie mark could be something related to the moon and a new concept, like a moon - flower that only blooms at night. She could use her powers to protect Equestria during the night, just like her mother, but also bring a new sense of hope and mystery to the land.
A common theme is identity. Since Luna is in a human form, she often has to grapple with who she is now compared to her pony self. Another theme is acceptance, both her accepting her new human form and the humans around her accepting this strange new being in their midst.