The air was charged as the two adversaries went silent. They stood in place, having entered a combative stance while watching their counterpart's movement. They both watched every single muscle move, ready to strike at any time.

Then, however, due to her short-temper, Nightmare Moon broke the silence. She yelled at the top of her lungs, her horn beginning to glow as she charged towards her foe.

Celestia stood in place as her rival drew closer and closer. The Princess of the sun may have been heartbroken, but she was experienced nonetheless: An able tactician and expert at reading others. She knew how to use those skills, having practiced them for thousands of years. She read Nightmare Moon like an open book. She simply had to find the right page at the right time.

Celestia bent her knees as Nightmare Moon was only a few meters away. She pushed herself off the ground, unfolding her wings and taking off into the sky. Nightmare Moon barely missed her, charging past where she had stood moments ago, directly into a solid stone wall.

A massive explosion erupted from within the throne room, whirling up dust and and throwing debris around the room. Celestia, still hovering in mid air, coughed as she was engulfed in a large dust cloud. She flapped her wings, trying to push it away, but to no avail.

Celestia covered her mouth with her right hoof as she looked around herself, trying to spot what was going on...or what happened to Nightmare Moon. Her search was useless though as she couldn't see further than one meter in front of her.

Then, however, she heard sounds beneath her. The sound of stones hitting the ground, followed by a loud groan.

The dust began to lift, revealing the sight of Nightmare Moon to Celestia. She was breathing heavily, covered in dust as she had yet to spot her adversary. It was clear to Celestia that this was a moment of weakness for Nightmare Moon. She hovered above her, able to strike at any moment.

Yet...it didn't feel right to her. She couldn't just strike her own sister down. She couldn't just end the life of the only pony that she truly cared about. She would never be able to look into a mirror anymore, as she would not see herself, but only a ruthless murderer.

But was this really her sister? Had she not seen her sister succumb to evil in front of her very eyes? Had she not sworn to eradicate evil once and forever? Clearly, the creature that used to be her sister now was nothing more but pure evil and hate.

Or...was it? Was it really pure evil? Or was there still good within her, beneath the burning hatred? Could her sister be saved from her prison?

Nightmare Moon shook her head as she got back to her senses, brushing off the dust that had settled on her head. She looked around in fury, scanning her surroundings for Celestia who still hovered above her.

Celestia took a deep breath, concentrating for a brief second before charging her horn. Nightmare Moon's ears twitched as they heard the almost electric sound of Celestia's charged horn above her. She looked up, spotting her foe as she dove down towards her, her horn charged with deadly amounts of energy.

Nightmare Moon unfolded her wings, flapping them once and creating a mighty gust of wind that catapulted her forward, out of harm's way.

Celestia hit the ground with so much force that the earth shook. Nightmare Moon covered her face and ducked as debris flew past her. When she looked up again, a big, gaping hole now was where she had stood mere seconds before.

Nightmare Moon used the few seconds she had to take a few more deep breaths, keeping a watchful eye on the crater at all times.

Then, however, Celestia emerged from within the deep crater, firing a mighty beam of energy towards her. Nightmare Moon managed to summon a magical shield in front of her just in time, effectively blocking the attack.

Nightmare Moon then turned the tables around, jumping off the ground and skyrocketing into the air. A dark blue beam headed towards Celestia, which she barely managed to dodge.

Nightmare Moon shouted in rage at her missed attack and fired yet another powerful ray of energy at her foe. Celestia hersef fired a beam at Nightmare Moon, causing their two beams to collide in mid air and explode. The two of them were thrown around the room as if they were nothing but toys. Celestia now laid on the ground, marked with scratches and a bleeding nose while Nightmare Moon was smashed into the throne, causing it to fracture as she hit it.

The two of them coughed and groaned in pain as they laid on the ground. Nightmare Moon rolled her head around to see a big crack in the golden throne next to her. This, undoubtedly, enraged her.

Nightmare rose to her hooves in an instance, empowered by the image of the damaged throne. She walked up to the throne and laid a hoof on the fissure.

"No..." She mumbled to herself. "I cannot break. Not now, not to her."

The sound of Celestia's groaning filled the room as she attempted to get on her hooves as well.

"I must defend what is right, protect those who cannot defend themselves." She pulled back her hoof from the throne. "I must destroy this cursed evil. Once and for all!"

Nightmare Moon turned and saw Celestia struggle on the ground. Celestia looked weak to Nightmare Moon, unable to even get on her hooves again while being covered in painful scars. Nightmare Moon smiled as she smelled the scent of victory.

All was silent as Nightmare Moon stepped closer to Celestia, her hooves clacking as they hit the ground. Celestia could do nothing but wait for her fate it seemed. She saw her foe, her very own sister, step ever closer to her. It was surreal to her, that her own sister would strike her down.

Nightmare Moon's horn began to glow and shimmer as it charged up a powerful spell. One that would end Celestia once and for all.

The two adversaries looked at each other in silence as Nightmare Moon stood only about two meters away from Celestia. Only the sound of Nightmare Moon's glowing horn filled the room.

"You are a disgrace to all ponies in Equestria." Said Nightmare Moon with disgust in her voice. "Not only a disgrace, but a threat to all that is good. I will, at long last, bring justice to Equestria by destroying the great evil that has plagued us for so long!"

Celestia's eyes narrowed at her foe's speech. "Justice is determined by the hooves that claim it, sister." Celestia replied, causing Nightmare Moon to grumble. "The things you call evil might be justified and good-willed to others, villains may be heroes to others."

Celestia coughed, taking a deep breath. "Things in life are not as black and white as they seem to us, sister. They never are." Celestia paused, closing her eyes for a moment before looking Nightmare Moon in the eyes. "A leader can only call themselves righteous and great if they take all perspectives into consideration, not just their own."

Celestia saw Nightmare Moon flinch backwards. A single tear rolled down her cheek as Celestia's words managed to reach her heart. For that one second, Celestia saw that her sister was, indeed, still alive. She was not lost, not destroyed by evil. At least...not yet.

Nightmare Moon shook her head with a loud grumble, baring her sharp teeth at Celestia.

"I will not give in to your lies! You may have been able to deceive others, perhaps all of Equestria..."

Nightmare Moon paused, her horn glowing brighter than ever before as she stepped closer to Celestia.

"...But I will NEVER be your puppet!" She shouted at Celestia.

In the very second that Nightmare Moon attempted to shoot the deadly beam at her foe, a rock hit her face. She staggered for a brief moment, quickly looking back at her foe who now stood on her hooves once more.

"Hatred alone will gain you nothing but defeat. It makes you blind, foreseeable." Celestia said with a calm voice, talking as if their fight was nothing but practice for her.

Nightmare Moon was enraged by her adversary's mocking tone. "The only one who will face defeat today...is you!"

A sudden, deep blue beam was shot towards Celestia, who barely managed to dodge it by lifting off into the air. Nightmare Moon followed suit, also lifting off and hovering in the air.

Nightmare Moon charged her horn yet again, this time deciding to flap her wings as fast as she could, charging towards Celestia for a second time.

Once again, her charge missed. Nightmare Moon turned around to see that Celestia had left the throne room, flying out of a big hole in the ceiling.

"Come back here! You cannot escape your fate!" Nightmare Moon yelled after Celestia as she flew through the hole in the ceiling as well.

She looked around for a brief moment, quickly spotting Celestia in the near distance. Nightmare Moon flapped her wings as fast as she could, slowly reducing the distance between her and Celestia.

Celestia looked back, spotting Nightmare Moon behind her, inching closer and closer. She knew she wouldn't be able to outfly her in the long run, she had to do...something.

Celestia gasped as a deep blue beam shot past her. She took evasive action as yet another one was fired, missing her. Nightmare Moon came closer and closer as Celestia had to fly crooked lines in order to not get hit.

Celestia used all her energy as her target, an old, ancient temple, came into sight. She breathed heavily, leaving out breaths as she accelerated, beginning to outfly Nightmare Moon behind her. Celestia could hear Nightmare Moon behind her, still close behind her, keeping up with her.

A sudden cry of agony filled the air as Celestia was engulfed in a fiery explosion. Her loud, initial cries of pain died off in a matter of seconds, and Celestia was rendered unconscious. Nightmare Moon stopped, her horn casting a light smoke trail due to the intense amounts of energy Nightmare Moon used. She smiled with joy as the unconscious, seemingly already lifeless body of the Princess of the sun fell out of the sky.

Nightmare Moon's smile intensified as Celestia disappeared beneath her, falling into a dense forest: The Everfree forest.

As if saved by a guardian angel, Celestia managed to survive the deep fall, landing in a lake inside the forest. The sudden, cold water was like a waking call for Celestia, and she came back to her senses. Her body was weak, yet she managed to swim back up to the surface. She gasped, taking a deep breath as she reached the surface. She hectically looked around, looking for Nightmare Moon as she scanned the treeline.

Nothing. Celestia's heart slowed down a bit as she realized she was undetected. At least for now. She paddled her hooves, swimming towards the shore of the lake. Celestia coughed as she left the water. Water dripped down onto the dirt as Celestia shook around, trying to dry her wet coat at least a tiny bit.

Finally, Celestia spotted an object, no, a building in the near distance, not too far away. She leaned forward slightly, her vision still blurry. When her eyesight sharpened, she almost immediately recognized what the 'building' in the distance was.

With new found strength, Celestia ran off into the jungle-like forest, heading towards the building in the distance. Celestia felt a stinging pain all around her body, as if her entire body told her to simply stop, to sit down and rest, to simply give up. Celestia's will, however, was unbroken. When others stopped, when heroes failed and fled in fear, she would, at all times, stand tall. She would always, no matter what, protect those who she had solemnly sworn to defend until her last breath.

Celestia was aware that she may take her last breath if she did decide to face Nightmare Moon a second time. She knew that she was in no condition to take yet another hit. She knew that her words would show no effect on her. It seemed like all odds were against her, like surrendering and giving in was the only option.

But Celestia was not defeated, not just yet. She had one, one last final trick up her sleeves. She had promised to herself, and hoped, to never use it, to only use it whenever the future of Equestria was at immediate danger. And, unfortunately, this moment was now. Celestia would have to use this secret weapon against evil. An evil that was her sister.

A few tears flowed down Celestia's cheeks as she hastily made her way through the dense forest. Celestia attempted to focus, to push out the thoughts of sadness that were hidden deep in her mind, but she increasingly lost control over them. More and more her thoughts were flooded by images and voices. She saw Luna's face, her hurt and sad face as she was sitting in a dark room. All alone. Celestia knew it would come to all this. She knew she would cause her sister great pain, that she would lose her beloved sister forever.

Yet, the worst part, Celestia thought, was that she had no choice. It needed to happen. May it be for protecting Equestria, herself or out of heroism, it was no matter to Celestia. She had to do it, and there was nothing else, no alternative, that could be done.

Celestia sighed as she left the dense forest, now standing in front of the previously distant building. The Castle of the two sisters. Yet another tear rolled down Celestia's face as she remembered the good time Luna and her had back when they built the castle. "You can't do it alone" Said all the other ponies around them. "Nopony could do such a thing alone."

Luna and Celestia proved them all wrong, and together they built a castle that would act as a home to the two of them, one that they would visit whenever their duties as rulers did not require them to be in Canterlot.

Celestia's head sunk as she let out another sigh, this time a quiet, sad one. Celestia sorted her thoughts for one last time, taking a deep breath, lifting her head and making her way towards the castle.

The drawbridge of the castle was open, as it usually was. Celestia walked over it, her hooves creating dampened clacking as they hit the wood. When Celestia was halfway across the bridge, she noticed that she was certainly not the only one in the castle. The first thing she noticed was that all the torches and candles were lit. Although this would seem like a minor detail to many, it was the first thing Celestia noticed, considering that Luna and her always, no matter what, blew the candles and torches out. When they were small they would always do a leg-up, helping each other as they did the same thing for all the torches on the walls.

Then they grew older, getting bigger. They didn't need each other's help anymore. To Celestia now, when looking back...she realized that the bond between her and her sister became a loose one. She'd tell herself that she loved Luna over anything and anyone in Equestria, that she would do anything for her, to protect her.

Yet...she felt like she never ever truly honored those words. To her, now, it seems like those were words she said to simply reassure herself, rather than actually caring for her sister and protecting her.

And now...that got back to bite her. She left her sister unprotected, did not care enough about her well-being. And now...her sister was nothing but an empty shell. A puppet of evil. And it was all Celestia's fault. She let this happen.

And now, she had to end it.

Celestia walked up the spiral stairs, noticing the blue banners as she looked at the walls. They all showed a depiction of Nightmare Moon, instead of Luna and Celestia. Celestia, before any doubts or thoughts happened to fall upon her, looked straight ahead once more.

She saw the door to the throne room in front of her, at the end of a short hallway. Celestia, with heavy heart, walked forward, the clacking of her hooves echoing through the castle, filling the air. Celestia gulped as she noticed that the door to the throne room stood half open. There was no doubt now. She would face Nightmare Moon, one last time. This time there was no going back. Only one of them would leave the room she was about to enter.

Celestia then arrived at the door. She carefully and quietly put her right hoof on the door, moving it and making it screech quietly. She immediately spotted Nightmare Moon, who sat on a big, deep blue throne at the opposite end of the room. Celestia noticed that the second throne, hers, was missing. She figured that Nightmare Moon must have gotten rid of it already.

Celestia then proudly walked into the room, stopping halfway, staring her foe into her cold, slitted eyes.

"Alive...?" Nightmare Moon said to herself. "Heh, I commend you for your effort. I thought you dead already."

Celestia remained silent, continuing to stare down Nightmare Moon who, quite obviously, was not impressed or serious about her. Celestia knew, with absolute certainty, that Nightmare Moon thought herself victorious already. Celestia knew that this, if anything, would be her downfall.

"No matter." Nightmare Moon said with a shrug. She slowly rose from her throne, giving out a short, evil giggle as she did so. "I suppose I should be grateful. I will take your life in person, while looking you into the eyes, seeing how the last bit of life escapes your body." Nightmare Moon liked her lips as she played with the thought in her head.

"I suppose we should not waste any time." Nightmare Moon said, her horn beginning to glow in her deep blue color. "I have to tell my subjects that their oppressor is finally gone."

Celestia took a deep breath before slowly opening her mouth. "Many thousand years ago..." Celestia began, closing her eyes briefly as a tear escaped her right eye. "I swore to never let anyone or anything harm you, Luna."

Nightmare Moon was about to lash out at Celestia for calling her Luna, yet she kept quiet as Celestia continued.

"I swore to protect you, that I loved you more than anything else in Equestria..." She paused, sobbing quietly. "...I'm sorry, Luna. I'm sorry to have failed you. I'm sorry to have lied to you. I'm sorry to have disappointed you. I'm sorry to not have given you the attention you deserved, to not have given you the love you deserved."

Celestia closed her eyes, her horn lighting up dimmly. "I am sorry. I am sorry for all the wrong I have done you, sister."

The ground in front of Celestia suddenly began to move, slowly revealing a hole in the floor. "But...above all of that..." Celestia said, looking back at Nightmare Moon, whose eyes, just for a second, looked like Luna's. "...Above all of that, I am sorry for what I will do to you. For what my duty demands of me and what my own mistakes have caused."

Nightmare Moon gasped as six crystals were lifted out of the hole in the floor, covered in Celestia's yellow magical aura.

"The elements..." Nightmare Moon said in shock. "The elements! You hid them here all along?" Nightmare Moon shouted, stomping a hoof on the ground with great force.

Celestia pulled the six crystals towards her, sobbing as she saw the image of her face on the surface of the crystals.

"I promised to only use them in situations of immediate danger. Situations in which the future of Equestria is in danger."

Celestia paused, closing her eyes as the six elements began glowing in their respective colors.

"...I'm sorry, sister."

"No..." Nightmare Moon said. "No! No!" She yelled, charging forward towards Celestia.

Celestia, her eyes still closed, began to tear up as she finalized the spell.

"Forgive me..." She said with a quiet mumble, inaudible over the enraged yelling of Nightmare Moon.

A sudden explosion erupted from within the castle. The castle fractured and broke in many places, tearing down much of what Celestia and Luna had so tediously built up.

Celestia felt an immense force originating from right in front of her. She felt as if she had lost control of the elements, as if something went wrong. Her hooves began to slide across the stone floor as the force of the explosion pushed her away. Celestia tried her best to hold against it, but eventually failed and was thrown around like a little toy, smashing against a stone wall with her back.

Celestia moaned as her eyes opened. Her vision was blurry, her head aching and her heart felt...broken. Celestia rubbed her eyes as she still laid on the ground, next to the wall she had been thrown into. She looked around, spotting the six elements of harmony laying on the ground where she had previously stood.

But...her sister was missing. Where Nightmare Moon last stood now was...nothing. Celestia looked around the room, scanning her surroundings for any sign of lifeform. But...she had no success.

Then, however, she heard something that attracted her attention. Her head turned to where the noise was coming from, a window at the end of the room, whose curtains were flapping in the breeze.

Celestia, as if magically attracted by the window, stood up in a haste and made her way over to the window, walking past the elements of harmony as they laid on the ground, still glowing.

And then Celestia saw what had pulled her towards the window, what there was for her to see. From the window, she had a perfect view at the moon, the window hanging just above the tree line of the surrounding forest. Tears rolled down Celestia's cheeks as she stared at the sight of the moon. A moon that now carried the image of a wicked mare. The Mare in the Moon, as it would later be called.

To Celestia, however, it was no wicked mare, nor evil. What she saw...was a sister, her sister. The sister she loved, the sister that she promised to protect and defend until her bitter end.

...was now trapped inside the moon, paying for Celestia's mistakes.

Celestia broke out in tears, crying like she had never done before. She rested her head on the railing of the window, occasionally looking back up, seeing the image of her sister and beginning to tear up once more.

"Sister..." She moaned between her sobs. "Come back, sister..."

"...I'm sorry."

Author's Note

It took me far too long to complete, but I finally managed to get the finale done.

I hope you enjoyed this chapter and this story as much as I enjoyed writing it!
Please, do consider rating the story and leaving a comment, I really want your feedback