Five doesn't remember her name, or her parents, but such things are irrelevant. Like all unicorns with magic specialization she was given to the personal care of the Fuhrer herself, Ascended when it came time for her to fight for her country. She will give her life for her cause, and that is all she needs know. Her wings, her horn, her strength- none will fail her in her in her life-long mission to protect her country, and all the ponies that live there.

But there are darker things on the horizon: forces, long locked in stasis prisons, are beginning to awaken, and the Fuhrer has given her the mission that she has been trained for her entire life:

Gather six of the finest soldiers in the Solar Guard.
Prevent the fall.
Save Equestria.