One idea could be that Trixie and Twilight Sparkle team up to solve a mystery in Equestria. Maybe a powerful magical artifact has gone missing and their combined knowledge of magic is needed to find it.
A common theme is friendship. Since Twilight and Trixie are both from the same universe, many fanfictions explore how they can become friends despite their differences. Another theme is magic. Given that they are both magic - users, stories often revolve around their magic skills and how they can learn from each other. Redemption is also a theme, especially for Trixie who has had some not - so - great moments in the original series.
Fluttershy could also be included. Imagine a scenario where Trixie is trying to put on a big, bold magic show and Fluttershy's timidness contrasts with that. Twilight might be caught in the middle, trying to make sure Fluttershy doesn't get too scared and that Trixie doesn't feel like her show is being ruined.
Well, there's this fanfiction called 'Twilight and Trixie's Team - Up'. In it, they have to work together to solve a mystery in Ponyville. It has a great plot that keeps you hooked. Then there's 'Trixie's Lesson in Humility' where Twilight teaches Trixie some valuable lessons. Also, 'The Enchanted Encounter' is a fanfic that features a chance encounter between them that leads to an unexpected adventure.
One theme is self - discovery. Trixie might be trying to find her place in the magical world, and Twilight can help with that. Also, the theme of adventure is quite common. They go on all sorts of adventures together, exploring new places in their magical realm. And sometimes, there is a theme of redemption, especially for Trixie if she has made mistakes in the past.
The appropriateness of a 'twilight sparkle diaper fanfic' is highly subjective. Some people might find it completely inappropriate due to the rather strange and unorthodox combination of the character and the diaper concept. Others, if the story is written in a very innocent, perhaps even child - like way, might see it as just a creative and quirky piece of fanfiction. But overall, it's not a type of fanfic that would be considered appropriate for a wide - ranging and diverse audience.
An 'evil twilight sparkle fanfic' is simply a fan - made fictional story where Twilight Sparkle is portrayed as an evil character. Fanfic writers might do this to add a new and unexpected twist to the familiar My Little Pony story. It could be inspired by things like exploring what would happen if Twilight's thirst for knowledge turned into a more self - serving and malevolent pursuit, or if she was corrupted by some dark magic.
Well, there is a fanfic called 'Twilight and Trixie: A Bond Forged in Magic'. In this one, Twilight helps Trixie overcome her insecurities about her magic skills. And also, 'Twilight and Trixie's Celestial Journey' is quite interesting as it takes them on a journey through the stars.
I'm not entirely sure specifically as it could refer to many different fan - created stories about Twilight Sparkle that have been forgotten. It might be a fanfic that was once popular but has since faded from the spotlight, perhaps due to new trends in the fandom or simply being lost among the vast number of fanfics out there.
There's a fanfic called 'Mermaid Twilight and the Enchanted Pearl'. In this story, Twilight, as a mermaid, is on a quest to find a powerful enchanted pearl to save her underwater kingdom. It's full of action and interesting characters, like her mermaid friends who each have their own unique abilities and personalities.