What is left to believe in when you are betrayed by your own?
The Honest
The Generous
The Loyal
The Kind
The Laugh
My friends?…they died long ago.
Twilight is forced to live the horrors of a real war on operation Sands of the Hourglass, what she lived, saw and learned made her realize that Celestia/Solar Empire were about to change Equestria for the worst and impulse her to take drastic actions, turning her friends and the empire against her. (Luna defects from the former Diarchy that ruled Equestria for finding Celestia's action severe and drastic)
Under the command of the Lunar Republic Twilight is now deployed on Equestria to bring down the Solar Empire and the Sol Invictus unit. Under the wing of Luna, Twilight is now a full trained and forceful soldier, together they developed a deathly combination of close quarters combat and magic.
After the events of operation Death Harmony Twilight now sees that the only way out of this conflict is to strike out and pave her on way, creating her own force of mercenaries known as the Libertaires d'quinoxe. The ultimate goal is to set themselves as the new power in Equestria and bring harmony back to the land once again.
It's during this time that she faces an opposing mercenary force known as "The Sundowners" and she learns the truth behind her own existence, the elements and the ultimate fate of Equestria.