Well, that was a kick in the feels.
I've been there. Trying to keep to myself, not provoke more bullying, watching others being punished and being happy it's not me this time. And revenge fantasies. I've read Enders Game back then. Ender-killing-his-bullies really spoke to me. Had Eldritch Power given me the opportunity to do that, would I? I like sumirufus take in the comments on all this.
Anyhow. I really like how you use the medium. Soundtrack, fonts, how the text is presented, how soundtrack is used to set the mood (and it's a good soundtrack). I was not sold on how the backgrounds looked at first, but I got used to it rather fast. And I love the character art. And those panning shots.
The tension bulid up is great. And the "catharsis" did not feel cathartic at all. In the end it made me feel empty. And sad. Which I think was the point.
It's short, it's mean and it will stay with me. Congratulations. Well done.