Twilight would be devastated. She might go into a state of shock at first. Then she could become very withdrawn, shutting herself away in her library to grieve. Eventually, she would probably turn her grief into a determination to uphold her brother's values and use her magic to protect Equestria even more vigilantly.
One great 'mlp twilight sparkle fanfic' is 'A Canterlot Wedding' fanfic. It delves deeper into the emotions and backstories of the characters involved in the wedding. Another good one could be 'Twilight's Ascension' which explores Twilight's growth in magic in unique ways.
One great fanfic could be 'Twilight's New Adventure'. In this fanfic, Twilight Sparkle embarks on a journey to discover a long - lost spell. It's full of mystery and showcases her intelligence as she deciphers ancient texts. The author does a wonderful job of staying true to Twilight's character, making it a really engaging read.
A really popular one is the fanfiction that focuses on Twilight's relationship with her friends in the Equestria Girls setting. It shows how they support each other through school problems, boy - girl drama, and still manage to keep their magical bond intact.
Twilight Sparkle is a beloved character, so a death fanfiction would likely be quite controversial. However, it could also be a creative way to re - imagine the story. For example, her death could lead to a new villain emerging or a different power structure within the Equestria setting. It all depends on the author's intentions and how they choose to handle such a significant event.
Good MLP FIM Twilight Sparkle fanfics usually stay true to her character. For example, her love for books and knowledge should be present. Also, they often involve her relationships with other ponies, like her friends in the mane six. Fanfics that show her growth, either in magic or in her understanding of friendship, are also great. They might also introduce new and exciting storylines that fit within the MLP universe, such as new magical quests or challenges for Twilight.
Another place to look is Archive of Our Own (AO3). It has a diverse range of fanfics, and you're likely to find some great ones about Twilight Sparkle there. Some fans also share their fanfics on Tumblr, so it's worth checking there as well.
One common theme is the corruption of power. Since Twilight is a powerful unicorn, fanfics often explore how this power can be misused or corrupted, leading her to a darker path. Another theme is isolation. Twilight might be ostracized by her friends for her new, darker tendencies, which then further fuels her descent into darkness.
The plot is also very important. It should be engaging and not too predictable. Maybe it could involve Twilight learning a new magic or facing a threat to Equestria that she has to solve in her own unique way. It could also explore her relationships with the other ponies in more depth, like how she helps Pinkie Pie with one of her wild ideas while also keeping her focus on her studies.
There's also 'Sunset and Twilight's Adventure Beyond Equestria'. This fanfic takes them on a journey to a new land where they have to learn about a different kind of magic. It's full of exciting twists and turns as they face challenges together and grow as friends. It really delves deep into their characters and how they can rely on each other.