What do I need to work on as a writer?

I'm kind of a writer too. I write my own ファンタジー stories on this journal app I have. That's what I have to write my stuff on. It depends on what あなた think あなた really need to write your stuff. Do あなた know what kind of stuff to write? Do あなた know the sum または the plot of what あなた want to write? The setting? The beginning and the end? Just how the entire story is gonna go? The characters and their names? The main character? What all do あなた need?

Grammatically wise, あなた are doing a pretty good job, but when it comes to character diction, あなた could improve. For example, "no offense, but no" starts off really timid(more so in the vein of early Fluttershy) then gets suddenly short and direct(which is もっと見る in tune with modern Fluttershy). It's an odd piece of dialogue that sends mixed signals about Fluttershy as a character. Since あなた are using the human Fluttershy, I would take advantage of the triple dots and have her stutter once and while("w-well...you see..um..*almost to a whisper* I'm so, so, sorry, b-but I
c-can't...sorry..."). Keep in mind the stuttering thing it's useful for socially awkward または nervous characters as well.

Another example, of bad character diction, would be here: "Too Bad" Celestia being a motherly passive figure, wouldn't be so direct(think もっと見る Yoda(Star Wars) when 書く Celestia), it'll be もっと見る like this: "A truly essential 表示する would place equal amount of importance on the audience and the performance itself." Watch a bunch of clips of Celestia if あなた have to, but diction(especially in fanfics) is important when portraying a character.

I also thought あなた do Trixie's character better as well. Even though she is egotistical and boastful, あなた have it portrayed in a very flat manner. あなた have to remember her overdramatic superstar side with it, she isn't simply saying she is better than you, but that she empathizing how extraordinary she is through her talent. This is what あなた could say is the difference between Rainbowdash's "I'm Awesome" and Trixie's "Tricks up my sleeves". This is why she makes such a big spectacular event in getting something from the vending machine in the first movie. Trixie similarily to Tanaka(from DR2) is a creative 書く character. To make her work, and make sure they don't get repetitive あなた need to think of unique ways to stress their personalities. As a tip use キャップ locks to create different meanings and/or emphasize words(i.e WHAT did あなた say? What DID あなた say?).

Also, as a side note, Dangaronpa and Undertale being text and character-driven games are great places to look when doing character writing. I honestly, wouldn't have known how to critique your fanfic if I haven't been such a big ファン of both DR and UT. Both do an amazing job at creating an atmosphere around their characters(and character diction is important for that).