Rainbow Factory/YMMV

Canon Defilement: Big time. What Cupcakes does to Pinkie and Sweet Apple Massacre does to Big Macintosh, Rainbow Factory does to Rainbow Dash.
Complete Monster: Rainbow Dash oversees the murder of ponies every day, but what firmly rockets her into this territory is how she's implied to murder Scootaloo, the closest pony she had to a little sister, in cold blood. It's explicitly stated that Scootaloo's failure at the flight test, sealing her fate, kills the last kind feelings Rainbow Dash had and irreversibly turns her into a merciless monster.
Crowning Music of Awesome: Glaze's original song this fanfic is based on, and most of its remixes.
Ear Worm: The song that inspired the fic.

In the Rainbow Factory, where your fears and horrors come true....

High Octane Nightmare Fuel: The whole damn thing.
Hilarious in Hindsight /HarsherInHindsight /FunnyAneurysmMoment: G3 Rainbow Dash is, shall we say, uncomfortable telling the other ponies where rainbows come from...

Minty: Wow, you know so much about rainbows!
Rainbow Dash: Of course I do, darlings! If I don't know all about rainbows, who would?
Pinkie Pie: Do you know how they're made?
Rainbow Dash: (uneasy) Ah, well, darlings...there are some things we're not supposed to know!

Ron the Death Eater: Canon Rainbow Dash? The most courageous, loyal, awesome pony you'll ever meet. Factory Rainbow Dash? A soulless and evil Corrupt Corporate Executive who murders Scootaloo, her surrogate little sister, in cold blood.
- Somewhat ironic considering the fact that she was the victim in another infamous fanfic...
- Corrupt Corporate Executive? Try more like a cross between an evil Social Darwinist of the "Improve the species at any cost" type and a death camp commandant, seeing as how this is specifically stated to be something the pegasi do to get rid of "failures".
Tear Jerker: Among other things, Orion's death.
- Every single adult pony they meet being EXTREMELY cruel to our three heroes.