Sweet Celestia

What really happened during the battle against Sombra all those years ago? Several cans of whoop-ass opened at once, that's what.

"She is our Shield, the benevolent protector of all ponykind. This was not always so. She was once a ghost, unfortunate enough to be forged anew in the fires of fate, and cursed to bear a sharpened edge that our foes would do well to beware."