Celestia and Nightmare Moon had been forced down toward the outskirts of the city. Flight was impossible overhead: the sky was awash with windigoes and golems, as well as several larger battleships. Worse, the dreadnought- -and its cannons- -still stood, looming over the Empire, its final defense against attack.
Then, from the distance, Celestia saw the clouds part. For a brief moment she was not sure what she was seeing. Behind the clouds, in the distance, an enormous plume of fire was projected over the Crystal Citadel. As Celestia watched, part of it broke off. A thin tendril of flames, siphoning the remainder of it.
She squinted, and at the very tip of it, she saw a formation of ponies. Ponies wearing the armor of her aerial squadron. They were driving the storm forward, pulling it behind them. Pulling it toward the dreadnought.
“What are they doing?! There’s no way they could- -”
Then they split. It was an asterisk formation; they turned outward, and the fire kept moving forward. Celestia noticed that one of them faltered, nearly going into a spiral- -only to be rescued by another.
The impact struck the hull of the dreadnought, burning through its surface as the entirety of the storm surged inside it. The sky was lit with magic and fire, the blast propagating outward and driving away both the clouds and windigoes as the sky-ship began to list.
“Remind me never to fight a war against your soldiers, dear sister,” said Nightmare Moon, watching these events unfold. “They are impressively reckless.”
“Why would you fight a war against my soldiers? We’re on the same side.”
“Twas a joke, dear sister. You know I would never fight against you or yours.”
The dreadnought began to fall. What Celestia had failed to do by magic, her soldiers had managed to do with bravery and creativity. She could not help but swell with pride.
Then something flashed at the top of the ship. As it angled downward, the bridge suddenly separated, tearing away from the doomed ship. At first Celestia thought it was simply breaking up from the strain, but then she saw it rising even as the rest of the ship fell, consumed in an enormous explosion of magic and fuel. The new, smaller ship steadied itself in the sky and was immediately surrounded by a geodesic force-field. The command center had survived.
“They just don’t give up, do they?”
“It appears to have no weapons. It should not be difficult to take it down.”
“But we need to move fast.” Celestia looked up at the sky. “We don’t have much time.”
Suddenly, she froze. Nightmare Moon did the same. They both shivered at the same time, sensing something strange. Up in the sky, Celestia saw a small but very bright star rising from the horizon.
“Nightmare? One of your stars is moving.”
Nightmare Moon’s eyes narrowed. “That is not one of mine. That is Venus.”
Celestia shuddered. “The Morningstar...”
Somewhere in the distance, an enormous mortar fired. The thud of the artillery piece resounded across the kingdom, and from the far side of the kingdom, in one of the last defended territories, Celestia saw a single shell fly into the air.
“An artillery strike.” Nightmare Moon raised a shield spell. “I see they are getting desperate.”
The shell rose into the air, and as it descended, Celestia saw a flash of explosive bolts as the sabot was cleaved in half. Whatever dark projectile it held inside extended a pair of black-feathered wings, and though to clumsy to fly on its own, it plummeted directly toward them in a controlled glide.
“Sister!” cried Celestia. “Watch out!”
She raised her own shield- -and felt something tugging at the inside of her mind, drawing out the formulae used to drive its construction.
The projectile landed just in front of the combined shields, her body igniting in sapphire light as a shockwave propagated outward, ripping the ice and stone from the ground in a wave of earth. Celestia cried out as the ground beneath her buckled. Her hooves slipped and skittered on the rapidly tilting stone as she desperately tried not to be subsumed by the explosion of force.
A hoof suddenly slammed into her chest, knocking the wind out of her and sending her reeling. The second hoof came to her face, striking with so much force that she was sure she lost teeth. Then she felt magic grasp around her neck, strangling her as she was picked up and slammed into the hard crystalline ground.
“SISTER!” Nightmare Moon leapt forward to her sister’s defense, only to nearly trip over something that had suddenly appeared in her path. She looked down to see a pony in strange, mottled armor. The pony looked up at her, her mask blank save for two luminescent spots behind a thick black plate.
“Out of my way!” she cried, striking down the pony who stood before her.
The pony looked up at her, her mask blank save for two luminescent spots behind a thick black plate.
“Out of my way!” cried Nightmare Moon, striking at the pony who stood before her. The pony dodged easily, as if she had already seen the blow coming. She deployed her own spell, freezing Nightmare Moon instantly within a large block of crystal. Nightmare Moon immediately compressed to vapor, slowly diffusing her way out of the crystal prison.
Celestia, meanwhile, was receiving a relentless beating. She was a sorceress; she had never been in a direct fight that did not involve spells. She could barely even defend herself; her body was simply too soft.
She saw a flash of magic. Her opponent raised a cutting spell, and slid it hard against Celestia’s right shoulder. It rebounded off the armor she wore beneath her wizard robes, and that gave Celestia the time it needed to regain her composure. She cast a bidirectional repulsion spell in a condensed form: when her opponent struck it, both ponies were blown apart from one another.
Celestia landed on her hooves, breathing hard and badly bruised. Her opponent did the same, but did not relent for any longer than the time it took fer her to land. That was long enough for Celestia to see her, though.
She was a pony clad in shining black, her armor marked with the insignia of the Crystal Empire. On her face she wore a mask that obscured all of her features; it was not unlike those that the thralls wore. What struck Celestia, though, was the sight of her long, gray-pink wings- -and her horn.
“Cadence?”
Penumbra leapt through the air, summoning a partial and unstable spell, preparing for another devastating shockwave. Celestia generated a personal shield, but before Penumbra could strike a black mist surrounded her and hardened into Nightmare Moon. Penumbra was thrown hard to the ground and rolled once before balancing herself and striking with an energy beam.
Nightmare Moon dodged the beam and fired one of her own, striking Penumbra in the chest. The blast knocked her back and sent her sprawling.
“Nightmare, DON’T! That’s Cadence!”
“Well it shouldn’t be a problem now. After a direct hit like that...”
Penumbra stood up, her armor completely undamaged.
“We have to get the mask off her! It’s the only way!”
“Fine, then.” Nightmare Moon spread her wings. “I shall take her down. You focus on the other one.”
“Other one?” Celestia turned her head, and suddenly found Thirteen standing beside her.
Penumbra changed targets seamlessly, forming several dispersion spells and firing a barrage toward Nightmare Moon’s chest. Nightmare Moon flipped and dodged, avoiding the beams and closing ground. Penumbra immediately switched to hoof-to-hoof combat, her preferred strategy. She jumped into the air and struck downward hard, aiming for Nightmare Moon’s horn to incapacitate her magic. She expected a defense spell, and she prepared for it, drawing on the instructions relayed by Eternity.
But instead, Nightmare Moon dodged, sliding out of the way effortlessly. Penumbra took a silver-clad hoof to the neck and immediately fell. She rebounded, dodging and rolling to one side before bracing herself on her back legs and springing at Nightmare Moon’s knees. Nightmare Moon shifted her weight easily, and Penumbra cried out as her knees buckled behind her. Nightmare Moon had struck her in the back of the knees.
Penumbra stood and continued to fight, as she had been taught. Her motions were smooth and fluid, but Nightmare Moon’s lithe grace exceeded hers by far. Penumbra had of course seen Nightmare Moon in her dreams, but it had not been like this. In the flesh she was flexible, strong, and perfect. Penumbra had never seen a more beautiful pony. Perversely, that only lead her to fight harder. This pony was her mortal enemy, yet she found herself wanting to impress her more than anything.
Celestia, meanwhile, raised a barrier shield between herself and Thirteen. “I don’t want to hurt you,” she said. “If you surrender, we can talk this out. We don’t have to resort to violence.”
Thirteen did not respond. Her horn lit, and her own magic sizzled over Celestia’s shield, disassembling it with a puff and a flicker. Celestia stared wide-eyed. “How did you do that?”
Thirteen did not answer. She just kept staring, although inside her helmet, she was carefully tracking Penumbra’s course and path.
“I’m really sorry about this,” said Celestia, “but I can’t let them keep fighting. I have to save my sister and little Cadence!”
She lowered her horn and fired a bolt of solar magic. As she did, Thirteen vanished, teleporting elsewhere.
“Wait, what? You can’t do that!” Celestia looked around, confused. “Nopony can teleport! Only I can do that!”
Thirteen reappeared- -and then reappeared again, and again, and again. Suddenly, Celestia found herself surrounded. Then she heard a flash and felt a weight on her head.
“EEK!” she cried, suddenly jumping and bucking while Thirteen held on for dear life. “She’s in my mane! SHE’S IN MY MANE!”
Nightmare Moon’s head turned suddenly toward her sister’s cry, only to see her being swarmed by a pile of armored mares. “Sister!”
Penumbra saw her chance and took it. She slammed her power-armored hoof into the side of Nightmare Moon’s face. Nightmare Moon did not even flinch, although her otherwise enormous round pupils became distinctly slit-shaped as she slowly turned. Penumbra’s wings uncontrollably extended.
“You little horse. Can’t you see I don’t have time for you?”
Nightmare Moon slid forward. Penumbra moved to block, and felt a sudden blow to her ribs. The armor absorbed it, but not the subsequent plume of silver magic that sparked and crackled through her body. She rolled and dodged, only to be passed by a plume of smoke that immediately reformed into Nightmare Moon, followed by a sharp blow to the elbows. Penumbra dropped to her knees, raising a defensive spell.
Nightmare Moon flipped, rolling over the spell as her armor shifted. A piece of it meant to serve as a pauldron and bracer suddenly became a kind of silver liquid, sliding forward and assembling into a quicksilver blade. Eternity took control, raising a shield spell as the blade came down toward Penumbra’s horn. It sparked and rebounded, but Nightmare Moon pirouetted and struck again. The spell began to crack.
“No!” cried Celestia, now fully buried under a pile of Thirteens. “Nightmare, don’t hurt her! Just take the mask!”
Nightmare Moon sighed and cast a spell, just as Penumbra was leaping up for an offensive attack. Silver chains burst from the ice and soil below, twisting around her legs and body. Penumbra roared with hatred, but could not break free. She was pulled to the ground, and even the strength of her power-armor could not free her from Nightmare Moon’s magic.
“I won’t cut the quick. But this threat must not be allowed to persist!” Nightmare Moon brought her sword down.
Nightmare Moon sighed and cast a spell, just as Penumbra was leaping up for an offensive attack. Silver chains burst from the ice and soil below, but just as they emerged Thirteen appeared directly in front of Penumbra. With a single flip-kick, she struck Penumbra just under the chin, sending the alicorn reeling backward from the force. The chains wrapped themselves around Thirteen instead, chaining her to the ground.
Celestia watched this, and felt a strange sensation behind her eyes.
“Fine. Then you can end first.” Nightmare Moon raised her blade, but in an instant Thirteen teleported, landing on Nightmare Moon’s back. As she did, she cast a powerful gravity spell. Nightmare Moon cried out as she suddenly found herself overburdened.
“Now!” whispered Eternity. “Penumbra, take her down! UNZIP HER!”
Eternity triangulated a shockwave pattern. Penumbra summoned her magic and felt it rise in power from the amulet on her neck. Her entire body pulsed with its magic down to her very marrow, as if she were boiling inside her armor. She harnessed the energy and allowed Eternity’s instructions to take control, letting it burn through her horn toward the enemies of all free ponies.
The shockwave range out, and with each burst it formed an explosion of razor-sharp crystals. Thirteen immediately teleported out of the way, and the crystals struck Nightmare Moon, only for her to convert to a cloud of gas. Celestia raised a spherical shield and deflected the blow, bouncing away in the process.
The mist suddenly reformed around Penumbra, and she immediately felt a silver-clad leg around her neck as she was placed in a chokehold. She moved to break it, but found that she could not; as flexible and strong as she was, Nightmare Moon was even more agile and her grip only grew stronger as Penumbra struggled. Her view of the inside of her mask began to fade as black spots formed in her vision.
“Penumbra!” Even Eternity’s voice sounded distant. “You have to keep fighting! You’re the Empire’s only hope! They’re going to enslave your friends! DO SOMETHING!”
“I will protect them,” gurgled Penumbra. “Whatever it TAKES!”
She summoned an immensely powerful destructive spell. Nightmare Moon held tight, casting her own protection charm and forcing Penumbra’s horn to face away. At that angle, it would be impossible to do any real damage.
Penumbra cast the spell, and it rang out as it flew from her horn- -and then immediately reversed polarity as she pulled it back into herself.
She screamed in agony as the uncontrolled feedback tore through her body. With her own body acting as a conductor, the blast was transferred to Nightmare Moon. Unprepared for the surge of lethal undifferentiated magic, Nightmare Moon’s protection spell failed and she was thrown back.
“Cadence!” cried Celestia, immediately running to Penumbra. “That was a feedback surge- -hold on, I have a restoration spell- -”
She froze in horror as Penumbra stood. The feedback surge had shattered her bones and seared her nerve endings, but both were rapidly regenerating.
“Don’t do that,” warned Eternity. “That would have cooked a normal pony. You’re lucky your horn is still attached.”
“I am not a normal pony. And my name is NOT Cadence!” She reached up to her face and removed her mask. It had been damaged by the feedback surge, and she needed to see. She wished that she did not have to; after all, it had been a gift from Scarlet Mist. But the battle came first. Besides, Scarlet Mist could always make another.
Celestia’s eyes grew wide, and Nightmare Moon paused, unsure of what to do.
“Cadence- -”
“- -Is a stupid name. My name is PENUMBRA. Get it right, you fat horse.”
Celestia winced, but slowly approached Penumbra. “It’s going to be okay now,” she said. “I know you’re afraid, and probably confused, but we can help you. We came to save you. I’m not going to hurt you. See?” She raised up her hooves, and moved in for a hug. “It’s okay. It’s going to be okay- -”
Blue magic suddenly gripped Celestia’s lower jaw. She let out a muffled scream as she was pulled downward, then gagged as Penumbra’s knee crushed her throat. A second spell immediately grasped her wings, wrenching them to the side. Celestia squeaked in pain, unable to make any sound larger than a tiny gasp as she choked and wheezed.
Nightmare Moon raised her horn, preparing a devastating spell- -and Penumbra responded by using Celestia’s wings as a handle to position her between the two of them, using her as a pony shield and firing over her back.
“Curse you, Penumbra Heartbreak! CURSE YOU!”
One of Penumbra’s bolts struck Nightmare Moon in the chest. She was knocked back. The second also hit, but Nightmare Moon responded by turning to vapor. She moved swiftly across the ground and behind Penumbra; Celestia was too heavy to reposition effectively, and Nightmare Moon was able to reform- -but as she did, Thirteen appeared at her side, putting her hoof through Nightmare Moon’s body. Nightmare Moon reformed around it and cried out, her eyes wide with confusion. She immediately pulsed between a material and vapor state, and then fell to the ground as Thirteen released her.
Seeing her sister hurt, Celestia managed to regain some modicum of composure. Despite the pain in her wings, she was able to perform the calculations necessary to cast a powerful spell. Space around her shimmered and split, rearranging itself as fractals formed and interconverted to geometric shapes that swarmed Penumbra. She released Celestia, desperately trying to fight them off. Celestia fell to the ground and teleported to her sister’s side.
“Sister! Are you hurt?!”
Nightmare Moon shuddered. “I managed to stop myself from reforming at the last moment, but my organs feel...well, as one would expect...”
“Hold on. I can help.” Celestia lowered her horn to her sister and began to cast a healing spell. As she did, she heard an explosion and felt feedback against her mental processing matrix. Penumbra had broken through her spell, and was slowly walking toward the sisters.
“But the mask,” said Celestia, looking up. “You took it off- -”
“It isn’t the mask, dear sister,” replied Nightmare Moon, darkly.
“But then...” Tears welled in Celestia’s eyes. “Cadence! You can’t be evil! You just can’t!”
Penumbra stopped. Thirteen teleported beside her, watching.
“Evil? I’m not evil. YOU are. Look at my home!” Penumbra pointed out at the battlefield at the leveled and still-burning city where battle still raged. “YOU invaded it! YOU came to take what was ours! We were neutral, but that wasn’t good enough! My ponies, my friends- -you came to hurt them. To hurt ponies I LOVE. And I can’t let that happen.”
“You’re confused. Sombra has brainwashed you- -”
“You call it brainwashing. I call it the TRUTH. Maybe you wanted to raise me to be blind, but I refuse. I fight for FREEDOM. I fight for the Witchking! FOR SOMBRA!”
Penumbra charged, her whole body igniting with magic as she pushed forward, using her horn like a battering ram aimed straight at Celestia. Nightmare Moon rose, throwing her sister aside and drawing her sword. She dodged, her blade sparking as it cut through the surface of Penumbra’s armor, even as she was impacted by the force of the passing spell. Penumbra landed on her hooves, turning suddenly and preparing for another attack. Her eyes were lined with black paint, but they were not cold. She was not a slave, nor was she being controlled- -she had made her choice, and Celestia understood this, even though she refused to accept it. Nightmare Moon had been right.
“Cadence, please listen!”
“I am not CADENCE!” Penumbra summoned another garage, this one manifesting as multiple gatling spells. This time, Celestia was prepared. She cast her own shield spell, one on a randomly rotating density profile. Something reached into her mind, trying to read the data of the shield, but could not find it. The esoteric field relied too heavily on the Heisenberg principle, and Penumbra’s spell did nothing.
“In case you didn’t know?” whispered Eternity. “This isn’t good. You missed your chance to take down the weaker sister. Now she’s started to make up her mind. Once it does? Even together, we won’t be able to stop her magic.”
“Cadence, listen to me!” cried Celestia, her eyes streaming with tears. “You were supposed to be my daughter! You were supposed to be beautiful and kind! Why are you doing this?”
Penumbra dropped her Gatling spell and walked to the surface of Celestia’s shield. She lifted her head, and then plunged her horn into the dome. Her body was immediately wracked with feedback, and the pain was unfathomable- -but she did not deviate or hesitate. She thought of the ponies waiting for her, of Crozea, Scarlet Mist, Holder and Zither, of Chrysalis, Facet, Burnt- -and of her father. The amulet around her neck began to grow, and forced more power into her horn. Her body was burning, but it hardly mattered. So long as she recalled those who she loved most, she could withstand the pain.
She looked up through the distortion of magic and feedback, and her eyes met Celestia’s. “Galen the Griffon,” she said. She saw the confusion over Celestia’s face, and that only made Penumbra’s rage increase. “You don’t even remember him! Let me remind you! He was a poet, a traveling minstrel, and he helped his friend- -MY friend- -with an ambush- -and you slew him! Zither Heartstrings! You took his legs! You took his LOVE! Is that what ‘peace’ and ‘harmony’ means?! Slaying those who don’t fit your design, as you would my father? As you would ME?!”
Celestia blinked, and a look of recognition crossed her face.
“I remember,” she said. Her face was painted in shame, and she could no longer meet Penumbra’s gaze. “They took me by surprise. I attacked. I...I wasn’t myself. I couldn’t control it. Ponies got hurt because I forgot who I was, but I remember the griffon. He was burned and hurt, but I saved him. I used my magic to protect him. But he would not let go of...of...” Celestia winced. She could not describe what she had seen- -what she had DONE. “But I saved him. I brought him back to Equestria. He lived a long, full life. And every day I lifted the sun, he was there...there at the grave...” Celestia looked up. “But that was six hundred years ago. Griffons don’t live that long. And neither do unicorns.”
“You. Are. A. LIAR!”
Penumbra pushed her whole head through the shield. Overwhelmed, it began to tear her apart. Celestia watched in horror and was forced to abort the spell before the damage became permanent. Penumbra collapsed to the ground, sizzling and smoking. Yet even in that state, with her armor torn and burned and her body no doubt in worse shape, she managed to stand.
“You took my friend’s love. You made him sad. I think I understand. I really am a monster.” She looked up, and her eyes met Celestia’s. “Because all alicorns are. By definition.”
Before Celestia could offer any words of encouragement, Penumbra began to summon a spell. This one was different from the others. It was not formed from prefabricated pieces of a spell; rather, it was drawn from Penumbra herself, formed from instinct and the feelings flowing through her.
“You never tried to find him. You never tried to HELP him.” She looked up, her eyes alight with the energy from inside. In a flash, she teleported- -or was teleported. Suddenly she was on top of Celestia, her magic bearing down on her in a plume of fire. Celestia defended herself with a spell, but the force was so intense that it brought her to her knees. Penumbra kicked them out from beneath her, tackling Celestia to her side and standing over her.
“You call your self an alicorn,” she hissed. Her magic formed a construct around Celestia’s horn, closing tight around it. “You don’t deserve to.”
Then Penumbra began to pull. Celestia screamed and her wings flapped uselessly, but Penumbra held her down. She could feel something cracking through her magic.
“Stop! Please stop! CADENCE STOP!”
“I won’t let you HURT ANYPONY ELSE!”
Penumbra pulled hard, but before she could break the horn free, she suddenly felt a strange sensation. Her magic flickered and went out, and she looked down. For some reason she could not understand how Nightmare Moon could be on her left, her forehead against Penumbra’s neck, and how the tip of her long, pointed horn could be on the other side. Or why it was dripping with black fluid.
“I won’t let you HURT ANYPONY ELSE!”
Penumbra pulled hard, but before she could break the horn free, she suddenly felt a sharp shove to her chest. Thirteen had appeared in front of her and thrown her back, interrupting the spell. Penumbra did not understand why, and was momentarily angry, wondering if she had been betrayed- -when Thirteen turned, and Nightmare Moon’s horn stabbed her through the heart.
Penumbra’s eyes grew wide. “No,” she said. “You can’t- -you can’t do that! That was supposed to be me!”
“NIGHTMARE!” cried Celestia, watching as Nightmare Moon slid Thirteen’s body off her horn. It was dripping with silver, and a pool of the same color was forming beneath the armored mare. “What have you done?!”
“It was not meant to be her,” she said, her horn still dripping. “I was aiming for the alicorn.”
“You- -you were going to stab little Cadence?! WHY?!”
“She was going to hurt you. I cannot allow that. I simply cannot.”
Penumbra scrambled forward, grasping at Thirteen’s body. “You didn’t- -you can’t- -”
“Penumbra,” said Eternity. “Get ahold of yourself. She was expendable anyway.”
“I can still help her,” said Celestia, standing shakily. “Please, just let me try- -”
“Get AWAY!”
As Penumbra screamed a massive shockwave emanated from her, one hundreds of times more powerful than those she had summoned previously. Celestia wrapped a protective spell around herself and her sister, although both of them were thrown back at some distance.
Penumbra clutched Thirteen. This was something knew. Something she had never conceived of. Ponies could get hurt, yes, but this was too much. Ponies never killed. It simply never happened. But all too late Penumbra realized that this was her purpose. That this was what she would have done to her enemies. She thought she had been prepared. She had not been. Not even close.
Thirteen was still breathing, but her breath was slowing. Her armor was smeared with beautiful silver, as if somepony had spilled thin, watery mercury on her. In the Hyperborean cold, it was already starting to freeze.
“I can help you,” said Penumbra. “Eternity, I need a spell. I need a spell to fix this!”
Eternity was silent. Then she spoke, softly. “There is nothing I can do. But you have to listen, and do what I say VERY closely. That hole in her armor? I can see in her mind right now. It’s bad. It’s VERY bad. You have to get back. NOW!”
“I won’t leave her!” As she said it, Thirteen suddenly went limp. “Thirteen? No! Come on! I could have survived it! I COULD HAVE SURVIVED! I’m half dark unicorn! You’re NOT!”
There was no response, of course. But Penumbra did not let go.
The eyes on Thirteen’smask flickered and went out- -and then a single one ignited in the center.
“Host-operator vital signs lost,” said a voice. Penumbra looked up, confused. She recalled that she was alone in that she had once heard Thirteen’s voice- -and the voice that had spoken was not hers.
“Wh...what?”
“Engaging nanobotic resurrection. Please stand by for respawn.”
The silver covering Thirteen suddenly started to boil, rising up not as liquid but as metal, forming delicate spiders of machinery that scrambled across her body and back into the wound. Penumbra did not understand what was happening, exactly, but Emeth had taught her well the nature of nanogolems- -and what they were, at least in theory, capable of.
Celestia and Luna approached, one looking sad and both looking ready to attempt to remedy their mistake.
“It’s too late,” said Celestia. “I’m sorry Ca- -Penumbra. But once a pony has passed to the other side...there isn’t anything anypony can do. Not even us.”
“You have to make a choice now,” said Nightmare Moon. “It is only for my love of my sister that I do not allow you to join your heretical friend. Surrender now. You have no other choice.”
Penumbra looked up at them. She had to buy time.
“Now, at least TRY to listen,” said Eternity. “You’ve taken a RIDICULOUS amount of damage. Like, as in, you’re risking organ failure. In every organ you have. And a few you don’t. The amulet can give you power, but your horn won’t survive much more. You don’t have a chronoplexer to turn back time if you mess up. Your only option is to fight. Here. I have a spell. Use this. You probably will not make it, but you can take down at least one. Aim for Celestia. She’s fatter.”
“And has the better defense. No. I have a different idea.”
“Penumbra. Penumbra! Do what I say! You have to do what I say! DO IT! DO IT NOW!”
Penumbra ignored the voice in her head. She instead cast a different spell.
Nightmare Moon drew her sword, and Celestia raised a set of mobile shield drones- -but the spell drifted lazily around them. It was not an offensive strike, so the two did not know fully how to defend. Even Celestia, who had studied magic for longer than most ponies had been alive, had never seen anything at all like it.
Both alicorns suddenly blinked and shook their heads, unsure of what was happening. Then they looked at each other. Celestia immediately blushed.
“S...sister,” said Nightmare Moon, moving closer to Celestia. “You are a mess...but I never realized just how...well, how beautiful you are.”
Celestia giggled. “Me? Beautiful? You’re just saying that.”
“No.” Nightmare Moon removed her helmet. Her enormous starry mane flowed out around her, and Celestia felt her heart race. “I truly mean it. Such color...such kindness. If only I myself were not so hardened. If only I had not become so cruel...”
“No, no!” Celestia took her sister’s hooves. “You’re always there to protect me! You’re always so strong when I can’t be...so big...so powerful...” Her wings ruffled. “So...dominant.”
“And you. So innocent and vulnerable.” Nightmare Moon leaned closer. “Sister. I love you so much.”
“I love you too, Nightmare.”
“Sister, I want you. I want you now.”
Celestia gasped, but blushed as she did. “But- -but we’re sisters!”
“You know what they say...” Nightmare Moon began kissing her sister’s neck. “Princest is wincest...”
Penumbra smiled. Her spell was working, and working quite well. She was just not sure how it worked, entirely, but knew that it was rising to a crescendo and beginning to complete itself.
Then, suddenly, she dropped to her knees, overcome with nausea and pain. Something was wrong.
The spell was failing. Something was eating it from inside. For a moment Penumbra thought it was a defense spell, but the pain she felt was not like that of a feedback surge. It was different. She could feel everything within Celestia and Nightmare Moon’s hearts, and as she had pressed through the layers of their souls, she had struck something terrible.
She was overcome with waves of the most intense, unspeakable jealousy. Hatred, rage, anger- -things that had been hidden for years, for decades, for centuries, even, allowed to fester for all that time. They burned like a white-hot sun, and no love, no matter how powerful, could survive in its presence. Penumbra had not known that such a horrific thing could exist within a pony, that such evil could be contained so well for so long, even as it grew with every passing day. Her spell was directed between the two sisters, but so was this thing: absolute, unending hatred of one sister by another.
Her spell began to fail, and Penumbra dropped to her knees. She could not overcome it. She could not defeat the horrors that dwelt deep within Celestia’s heart.