Isolation is often seen in MLP sad fanfic. A pony might be excluded from the group for some reason, either because they made a mistake or were wrongly accused. This makes them feel all alone and sad. There's also the theme of unrequited love. A pony might have feelings for another pony, but those feelings are not returned, which can lead to a great deal of sadness.
Loss is a very common theme. It could be the loss of a friendship, like two ponies who were really close but then something comes between them. Another common theme is disappointment, like when a pony's hopes and dreams don't come true.
One common theme is self - doubt. Scootaloo often doubts her abilities, whether it's her flying skills or her place among her friends. Another theme is loneliness. She sometimes feels left out or different from the other ponies, which leads to her sadness.
One common theme is failure. For example, Rainbow Dash might fail at a big race or competition, leading to her feeling sad and disappointed in herself.
A frequent theme in 'mlp sad pinkie pie fanfic' is the change in her relationships. If a friendship in Ponyville sours, Pinkie Pie would be deeply affected. It could be due to a misunderstanding or someone else coming between her and a friend. These changes in relationships can bring out a lot of sadness in her character as she values her friends so much.
One common theme could be loneliness. Discord, being a chaotic character, might be depicted as lonely despite his power. Another theme could be redemption. He may struggle to be accepted and redeemed in the fanfic. And also, the theme of friendship lost and regained can be there, as he tries to fit into the world of ponies and deal with his relationships.
One common theme is loneliness. Fluttershy is often portrayed as a shy pony, so it's easy to write about her feeling alone, even among her friends. Another theme is self - doubt. She might question her abilities, like whether she's a good enough friend or caretaker.
The theme of loss can be quite prominent in these fanfics. Spike could lose a friendship or a special object that was important to him. This loss makes him sad and forces him to deal with his emotions. Another common theme is the struggle for acceptance. Spike tries to fit in with the ponies' world, but there are always barriers, whether it's physical differences or differences in how they do things. These themes all contribute to the overall 'sad' tone of the fanfics.
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.
One common theme is failure. Rainbow Dash is often portrayed as a very confident and capable pony. So when she fails at something, like a race or a mission, it can lead to a lot of sadness. For example, she might train really hard for a big event and then not perform as expected.
The theme of self - discovery is also common. Through their interactions with each other, both Fluttershy and Rainbow Dash may learn more about themselves. For example, Fluttershy might become more confident or Rainbow Dash might learn to be more patient. And of course, the theme of loyalty is there. They are loyal to each other, and fanfics often show how they stand by one another in difficult situations. This can be seen in many fanfics where one of them is in trouble and the other comes to the rescue without hesitation.
Overcoming differences is another big one. Ponies in MLP have different personalities, like Pinkie Pie's exuberance and Twilight's studiousness. Shipping fanfics often show how these differences can be bridged in a relationship. They might have to learn to understand and accept each other's quirks and ways of doing things. For instance, in some 'Twidash' (Twilight and Rainbow Dash) fanfics, Rainbow Dash has to understand Twilight's need for order in her studies while Twilight has to accept Rainbow Dash's daredevil nature.