“Luna.” The Lunar Princess paused. She knew that tone. She knew what had always followed, and her armoured head turned to face her sister. Celestia stood behind her, clad in gold-plated armour, scuffed and scarred from hours of battle, but otherwise looking exactly the same as she had before the battle had commenced.
“Leave us, Luna,” said Celestia, looking not at her sister, but at the minotaur in charge of the whole invasion. Luna became aware that her armour was getting warm to the touch, beyond what even hours of physical exertion could impart, and so the Moon Princess bowed her head, and turned around, and began to trot away from the minotaur.
“We shall see to the recovery of our ponies. Try to contain your powers, Sister.” The only response she got was the smallest of nods, as Celestia’s mouth hardened into a line, and Luna noted that the usual blues, whites and pinks of Celestia’s mane had shifted more into the reds and yellows.
The minotaur, emboldened by the departure of what he believed to be the greater threat, rose back to his hooves, and laughed.
“You have made a mistake, sending away your sister like that, Princess.”
“It is true that Luna is certainly better at warfare than I am. But do not assume that simply because I find it distasteful and unnecessary, that I am incapable.” With a blast of heat, Celestia’s mane and tail gave up on their ethereal, flowing form, and turned into a waving wall of fire.
“My mentors always taught me that violence is to be a last resort. To be used only when words, food, gold and allies fail. To never enjoy it, for it is anathema to all I am trying to accomplish. I believe that Luna skipped those lessons. I would rather not have fought, but I will admit,” said Celestia, a smile forming on her face. “That there is a certain perverse pleasure in violence, especially when dealing with one that has been as...irredeemable as yourself.”
The minotaur took a few steps back as he became aware of both the intense heat and pressure pouring of the mare he had dismissed as the negotiator of the two sisters. With two beats of her powerful wings that blasted hot air over the minotaur, Celestia rose into the sky, the air shimmering around her.
“Luna has access to the moon’s powers-shape shifting, illusion, healing and many more besides. She is a mare of many faces and talents. Unfortunately for you, the sun knows how to do only one thing-destroy.”
As Celestia rose further and further into the air, the minotaur became aware that everything around him was catching fire, and he seemed to be enveloped in a singular beam of light.
“And as the sun is an overwhelming force in the sky, so too is any mare who can draw upon its power in combat,” said Celestia, her voice echoing down to the minotaur, who had fallen to the ground again from the magical pressure being emitted from Celestia.
“You attempted to prevent the rise of Equestria. And as distasteful as I may find it, you will make a perfect example for those who would earn our wrath. Perish,” said Celestia, and the light suddenly increased in intensity, turning the area white.
***Time***
Far away, Luna stared at the column of light stretching from the heavens to the area where Celestia was, and watched it pulse once, twice, thrice. And almost as suddenly as it came, the column winked out, leaving only a pillar of smoke.
A few moments later, Celestia walked into the camp, her armour smoke-stained and discoloured from the heat.
“It is done,” was all Celestia managed, and then she collapsed. Luna covered her sister with a spare blanket, and then turned back to treating the ponies that had been fighting alongside them, giving the same answer whenever one of them asked what had happened to Celestia.
“She gave up her vow of non-violence, so that you all could be safe.” And so the legend of Celestia grew and rose.