This story ignores Season 6 and splits from the universe from "The Cutie-Remark".

During the last bits of the Cutie Re-mark, a new portal opens unexpectedly, dragging Twilight and Spike into another timeline. Without the spell, they are stuck in a timeline with the smell of war everywhere, a place where the magic of friendship is no more. To return to her timeline, she has to fix this timeline and end this ten year war against Starlight's regime.

But Twilight will realize that sometimes, she has to get her hooves dirty and commit horrible crimes to better the whole world and save her friends.

"Twilight, get your gun, get your gun, get your gun.
Take it on the run, on the run, on the run.
Hear them calling you and me,
Every Mares of Liberty.
Hurry right away, no delay, go today.
Make Celestia glad to have had such a lad.
Tell your sweetheart not to pine,
To be proud her mare's in line."

Parodied from "Over There"

Based on WW1.