Two Sides
They say that one should never meet their heroes. But they never say anything about not killing them.
Then again, it wasn't as if Twilight had any say in the matter as she made the lonely trek through the shattered ruins of the Royal Palace. She had already met Princess Celestia, and it was too late to take back their relationship. Years too late. In fact, if anything, hero didn't do justice to what Twilight used to think of her mentor. Princess Celestia was the one who had sent her to Ponyville. Without her, Twilight would've never amounted to anything more than a lonely bookworm. It was only because of Princess Celestia's unparalleled guidance--no, her brilliance--that Twilight met her friends and became the Princess of Friendship. It was only because of Princess Celestia that Twilight had created a life that she could be proud of, one full of wonderful friends, adventure, and memories that she'd cherish forever.
That was why this was so hard. That was why she wished that she didn't have to be the one to kill the princess.
Regret seeped through the scowl engraved on Twilight's face as she made her way through the castle’s abandoned halls, shards of shattered glass and piles of debris stabbing into the bottom of her hooves with each step. At the same time, a fiery resolve burned through her gaze. Regardless of the pain she was feeling, no matter how badly she wanted to collapse from the burden of her murderous duty and break down into tears, she forced herself to keep going. Until the pony she cared for above any other lay lifeless, she had to press forward.
Spike walked beside Twilight, hanging his head from a storm of emotion only Twilight could ever relate to. He really was a good friend for sticking by her side. He was more than a friend. He was a brother. And yet, he may as well have not been there. Despite his presence, Twilight felt more alone than she ever had before, because she was the one who had to kill the princess who could do no wrong.
As she made her way toward the throne room, darkness from the outside world crept through the shattered ceiling and windows, engulfing the hall. Now, nearly a year after the civil war had begun, months after the Windigos had come only to be driven out by disharmony too strong for even them to feed on, the sky was nothing more than an endless black pit. The stars were gone, replaced by a bottomless abyss that hung above every second of the day. What few clouds remained were blood red. Twilight thought back to her prior battles, back to when she still had victories. Despite the epic confrontations with beings such as the Pony of Shadows and the villainous trio, she and her friends had never bled. Nopony had bled. The battles had a certain innocence to them. Ponies got hurt, of course, but nopony ever died or even considered murder. Nopony had even said that chilling word, murder. But now, the bloody spectre of death was ever-present, a constant reminder to Twilight of what had to be done.
As she stepped toward the shattered door to the throne room, every step bringing her closer to the one moment she would never be able to take back, she couldn't help but ponder how many chances she had been given to prevent this tragedy. It all started a few months after Twilight's coronation as ruler of Equestria. Celestia was enjoying retirement alongside her sister, or so everypony thought. Out of the blue, on a day like any other, she came to the palace and told Twilight that she had grown bored of retirement and wanted to rule Equestria again.
Twilight was taken aback at first. Celestia had seemed so sure that retirement was what she had wanted.
Twilight returned the throne to her idol, of course. The way she saw it, the position of ruler had always been Celestia's to take back. Other ponies were less than pleased. Many saw this as the sad attempt of a former ruler to relive their glory days. Celestia had to move on, they said. A few had no issue with Celestia returning as ruler. After all, she had kept the peace for over a thousand years and led Equestria to its best days.
Twilight's friends were split as well, but she maintained that Celestia knew best. Celestia always knew what was right, and it was Twilight's job to make her mentor proud.
Luna stayed retired. After a thousand years on the moon, she had no trouble moving on from her role as ruler.
As so Twilight returned to her original duties as Princess of Friendship and founder of the School of Friendship, ready to take over for Princess Celestia whenever she decided to retire for good.
That was, until Princess Celestia publicly announced that she intended to never retire.
She had eternal life, she stated, and so it was only natural that she used it to lead her kingdom forever.
As happy as Twilight claimed to be from the news, she panicked. Ever since Princess Celestia and Luna had first announced their intention to retire, Twilight had internalized the idea of becoming ruler. It became her end-goal, the ultimate way to make her mentor proud. If she couldn't ever be ruler, then what was she to aspire to become?
Sensing the turmoil within her student, Princess Celestia made Twilight in charge of the School for Gifted Unicorns. Full of glee at the prospect of running two schools, Twilight accepted. She had all sorts of ideas on how to improve the school, starting with bringing in other species and renaming the institution as the School for Gifted Creatures.
Twilight dedicated herself fully to her schools for the next few weeks, until news broke out that Luna had come to the Royal Palace to speak to her sister, an event which reportedly resulted in an argument between the siblings and Luna storming out of the palace.
Her always anxious mind going to the worst-case scenario, Twilight raced to Princess Celestia and asked to know what had happened. She was ready for anything, from a disagreement over the color of the palace curtains, to the return of Nightmare Moon. Princess Celestia insisted that it was just a minor disagreement, though she never specified what exactly had happened. Twilight knew the royal sisters were the type to keep disagreements secret in order to keep up appearances, so she inquired further, but it was to no avail.
Twilight wouldn't get her answer until a few days later, when Luna gathered all of Canterlot for a speech where she called for her sister to retire. She stated that it was time for them to move on and let the next generation take over. The speech split the kingdom in two. One side believed that Luna was right and Princess Celestia should retire as originally promised. The other side believed that Princess Celestia was the best pony for the job and Luna was simply bitter, no different than when she'd turned into Nightmare Moon.
Debate between the ponies of Equestria led to protests, which led to rioting. Fed up, Princess Celestia called her sister to the palace so they could talk out their differences. What resulted was a violent fight. Nopony knew who started it, but within minutes it was clear that Princess Celestia had won. She always had been the older, more powerful sister. Consumed by rage, Princess Celestia banished not Nightmare Moon, but Luna, to the fires of the sun.
This one act turned the majority of the populace against the princess. Unable to see her mentor as the target of such vitriol, Twilight passionately defended Princess Celestia wherever she could. The only result was that the kingdom came to despise her as much as it did the princess.
Sensing that the powder keg was one bad decision away from exploding, Twilight pleaded with her mentor to return Luna. Breaking down into tears, Princess Celestia insisted that she didn’t have the power to undo her spell. But that wasn't what made Twilight realize just how terrifying the situation had gotten. Consumed by madness, the princess kept repeating to herself that she had let her kingdom down. Anything Twilight said to try to reassure her that things could return to normal didn't work. Worse, Twilight's words made her mentor wish that she wasn't cursed with eternal life. Gone was the regal, motherly monarch who Twilight could always rely on for strength. In her place sat a paranoid, terrified pony.
Fearing an uprising, Princess Celestia imposed martial law soon after and imprisoned any royal guard who spoke out against her. Not even Shining Armor was spared.
As the once harmonious kingdom of Equestria descended into tyranny, Twilight insisted upon everypony that her mentor was still a pony worthy of being ruler. Her friends, Spike included, tried their best to make her see reason, to open her eyes to the fact that Princess Celestia was not the wise pony they once knew. Disgusted by what she felt was betrayal, Twilight left her friends and returned to Canterlot to live beside her mentor. The way she saw it, every friendship she had made was because of the princess, and for that she would be eternally grateful, even if it meant her own death.
In the weeks that followed, Equestria descended into civil war. Not a bloodless affair like the battles of the past, but a war filled with bloodshed and death. The colorful skies transformed to a color palette befitting the new Equestria. In their last stand, Twilight's friends tried to depose Princess Celestia, only to fail. Only Spike escaped capture. The others were put in a dungeon deep below Canterlot, their execution date tomorrow.
It was only now, with her friends mere hours from death, that Twilight understood the severity of her errors. Consumed by blind hero worship, she had let the kingdom she’d sworn to defend collapse into ruin. She had chosen the life of one pony over that of thousands. She knew she could never make things right, but what she could do was put an end to this madness.
Anxiety transforming her gait into a stumble, Twilight entered the throne room. Princess Celestia was on the opposite end of the room, sitting atop her throne. The room was empty and filled with rubble. All of the royal guards were either in the dungeons or had died in the fighting.
Princess Celestia shot Twilight a murderous glare. She knew why her student was here, and yet mixed within her icy expression was the motherly warmth of the Celestia who Twilight still loved. It was a smile, so brief that everypony else other than Twilight would miss it, that let her know that the true Celestia was still there somewhere. Twilight didn't know what had happened to her mentor--what series of events had transformed her from the kingdom's wisest ruler into a monster--but whatever it was, it was time for it to end.
As Twilight peered into the princess' empty eyes, Spike hid behind her body, trembling. Twilight didn't blame him for being afraid. He had never seen a murder, and now he was going to witness two. The death of the princess, and the death of the idiot student who believed that her mentor could do no wrong.
Princess Celestia really had been like a mother to Twilight. If Twilight had to pick between her own life and that of her mentor, she would pick Princess Celestia's every time without hesitation. But this wasn't about her own life, nor was it even about her friends’ lives. For the sake of Equestria, blood needed to be spilled. Princess Celestia had wished for an end to her eternal life, and her dear student was going to grant that wish.
Twilight's heart was racing so fast that she wasn't sure how was she still alive. Perhaps it was her duty to the kingdom that kept her going. The taste of vomit stung the back of her esophagus, and every one of her breaths were labored. She was trembling, more than she would have if she were facing her own execution.
Ready to end the nightmare, Twilight charged up a magical beam powerful enough to kill an alicorn. It was aimed at Princess Celestia's heart. It would cut straight through, ending it all in the most painless manner possible. Her horn glowed with magic, casting a purple hue over the wrecked room. She didn't know why Princess Celestia didn't charge a beam of her own or cast a shield. Perhaps she wanted to die but didn't have the guts to do it herself. Perhaps all this had been Princess Celestia's way to make Twilight do the dreadful deed. One final friendship lesson.
As Twilight prepared to fire the beam, she gazed one last time into the eyes of her mentor. Of her idol. Of her hero. Of her mother. Of the one pony she owed everything to. If she had one wish, it was for the princess to turn into Daybreaker. It would've made this easier.
When Twilight fired, Princess Celestia's icy gaze melted into that of the warm mother who had never left.