Another ten minutes remained before the arrival of Celestia's forces. For most involved, these ten minutes were to be the longest of their lives. For one specific unicorn, however, ten minutes wasn't anywhere near enough.

The remnants of the Royal Guard shared the same collective thought as they limped away from the carnage, 'Just ten more minutes and it's over...'

Celestia flew ahead of those accompanying her, tirelessly beating her wings ever-harder, 'Ten more minutes until you're safe, Twilight!'

Twilight didn't halt her advance for a moment as she gazed upon the object of her hatred, 'Ten more minutes... Only ten more minutes... To make him pay...'

Calamity tore the spear from his neck before crushing it in his mighty claw, sending splinters flying in every direction. It had been his in the first place, yet it had pinned him to the earth for several minutes; the sheer force of the impact effectively scrambling his thoughts for the duration. As he righted himself, Calamity thought he sensed something familiar, the thing he was searching for. He took a moment to clear his mind of the pain-induced haze. It was still there. As far as Calamity's emotions went, he was about as close to excitement as he could manage. He jerked his head around in anticipation, searching for his master, the only true wielder of chaos magic - Discord.

Twilight galloped towards Calamity, keeping her pace steady as she advanced, not slowing or faltering despite the ever diminishing distance between them.

As he found the source of the chaos energies, Calamity's body slumped slightly. It wasn't his master. This was a pony, the same pony from earlier, the purple one. But something had changed in her demeanour. Her aura was now almost black, in comparison with its previous lavender hue, she was coated in deep purple armour, and her eyes now glowed blood red; not to mention the particularly dangerous chaos energies whirling around the pathetic pony. For a creature from a race so underdeveloped she had great potential. It would have to be stomped out. He was already late, and the master needed him now. He would not fail him.

Calamity stepped forward.

Twilight's hooffalls became heavier as her rage increased almost twofold, the monster - the demon - was looking at her with what she could only sense to be disappointment as it sauntered towards her, and it infuriated her. "Nine hundred meters!" Twilight hissed to herself through her gritted teeth, her voice now seemed deeper and reverberated slightly. Any normal pony would sooner have volunteered for a solo expedition to the moon than approach Twilight in this state. Hate seemed to seep from her and force itself into her surroundings. The grass where she stepped would curl up and die, the earth beneath it drying up and becoming as barren and infertile as desert sand. The air, still crackling around her, held some kind of stale quality; as if fury itself had suddenly decided it wanted a smell with which to be associated. This, in conjunction with the ever present stench of death and rot coming from Calamity, and the heavy amounts of magic in the air had a more than adverse effect on all life in the area. Small rodents in the immediate area died as their hearts stopped instantaneously, and the larger animals fled quickly, sensing the ever-present danger; parched leaves swept across Sweet Apple Acres as the trees slowly began to die.

"He'll pay!" she hissed again, louder this time. He was almost in range, "He'll pay!"

Calamity took a confident step forwards. No matter what weapons of magic this fledgling possessed, he could easily match it, if not return it tenfold. 'She isn't in control, rage clouds her judgement.' He waited, watching as she drew closer. The moment she stepped into range, it began.

Calamity lashed out first, a chain of bone shooting outwards from his one of his 'kneecaps', hinged at the 'joint'. It struck directly where Twilight was standing only a second ago. She moved with dizzying speed, almost beyond what could be followed by the normal pony eye as much more than a blur, dodging two downward swings of the chain before stopping sharply a mere few dozen meters away.

Twilight slammed her hoof into the ground, shattering a dry patch of earth as it materialised under her hoof. A huge column of earth shot upwards from beneath Calamity's midsection, crushing several bones in his 'chest' as the tremendous force nearly flung him into the air. He reared back, several shattered bones falling from his chest.

Without pausing to inspect the damage, Calamity swung the chain towards Twilight, prompting her to quickly dodge backwards. However, he didn't stop the swing, instead allowing it to make a full circle and plunge into his own chest. The pain would be worth the end result. As it retracted, the chain now carried a huge spiked mass with it, leaving it with an appearance resemblant of a morning star. He swung again, faster this time. Whilst this whelp wasn't a serious threat in the long run, she was delaying him; he was wasting time.

Twilight tried to dodge again, charging furiously at Calamity. She began to work more potent magics than before, her horn glowing intensely with a dark aura. But as Calamity's mace thundered into the earth behind her, it shot the attached spikes from it as shrapnel. Whistling through the air, a few of these collided with Calamity, who didn't seem to notice; they were too small to do him any real damage. Twilight, on the other hoof, felt one bite into her rear-left leg and howled in agony, tears of rage, pain and frustration once again forming in her deep red eyes as she collapsed beneath the shadow of the behemoth, her leg broken.

Calamity realised he had made a mistake, and a costly one at that; he had acted too carelessly in his haste. A chaos spell, no matter the novice level of its caster, was dangerous at best. Interrupting even the simplest ones could cause a catastrophe, and here he was, with such a spell aimed at his torso. Calamity only had time to give one reflexive response. He swore to himself in a tongue that, spoken aloud, caused the ears of mortals to bleed. The spell shot a bolt of pure chaos energy into him, exiting through the other side, leaving a hole the size of a boulder. He reared up once again, the horrific gurgling sound unceasing even as he regained his composure. The pain was incredible, but Calamity only found himself spurred on as he focused on his goal, 'She will die, now!'

Twilight stood shakily, her horn throbbing in agony in time with her heart. She set herself steady once again at the realisation that she was wasting time. She looked up at Calamity with a disturbing smile, one not too dissimilar from one that Rainbow Dash had pulled on one of their camping trips weeks ago as she weaved a terrifying camp fire tale describing the intricacies and 'terrible secrets' of the Cloudsdale Rainbow Factory. The fictional horrors Rainbow had weaved seemed almost laughable to Twilight now, compared to what she had suffered, and what the abomination before her would endure.

Calamity focused, drawing upon his more powerful magics. Even if it left him weakened, he couldn't afford to be delayed any more. The gurgling he had been emitting rose to a booming crescendo as hundreds of spines, resemblant of spider legs, jutted out from his back. The closest ones shot towards Twilight, who remained smiling disturbingly up at him. In an instant, she was gone, appearing once again a few moments later to the right of the small tower of spines that had missed her and now jutted from the ground. Calamity intended to end it there, her arrogance and her attempts to taunt him proving to be her downfall. One thin but razor sharp bone shot from the pillar.

Twilight had been expecting it, counting on it. Calamity was a creature of habit, she had realised. Most of his attacks were simple variations of his other, more favoured ones, and she remembered this one well. After all, he had murdered her brother with it. The red in her eyes now positively blazed, fuelled by her rage at the memory as she raised her hoof and snapped the bone from the pillar, removing Calamity's control over it. She wasn't smiling any more. With a glow of dark magic the bone embedded in her leg removed itself and levitated above her in tandem with the one she was just holding. With another wave of magic, he broken leg snapped back into place, though she gave no more than a whimper as she stared up at him with malice in her eyes. All of her studies in the magic of friendship couldn't help her here, this monster was beyond saving. 'But my other studies, particularly those of anatomy, could prove useful...' she mused, rage opening up options to her that she would never even dare to contemplate otherwise. Calamity could see, and even though he didn't have any 'eyes', he must have had nerves behind the holes in his skull to be able to perceive the world around him. Sensitive nerves. She roared and launched the hovering bones like spears, aimed directly at Calamity's 'eyes'.

Calamity threw his weight forwards, dozens of spines following suit.

Twilight didn't move, this had to be timed just right.

"NOW!"

'NOW!'

Twilight was the first to react, teleporting away just as Calamity shot the spines in a cross-stitched pattern, tearing up the solid earth where she had been stood a fraction of a second ago like tissue paper. The projectiles she had fired hit him, boring themselves into his skull, tearing through the nerves within. The constant gurgle that Calamity had been emitting ceased suddenly, replaced by a whine that sounded like thousands being burned alive, their voice boxes melting together horrifically. It was then that Twilight realised that these nerves were not Calamity's. Although he could still feel pain through them, they belonged to each individual, pony or otherwise, intertwined with his body; they felt the pain as much as he did.

She didn't care, "If you hadn't become a part of him, he wouldn't be so powerful. He wouldn't have killed my brother..." she spoke calmly, judgementally, condescendingly. It was their fault, almost as much as it was Calamity's himself. His body teetered for a few seconds then collided with the earth as his legs gave out, the spines on his back now splayed limply across him. Even face-to-face with him, and even after having grown taller, Twilight still had to look upwards just to stare the beast in his now destroyed eye sockets. She smiled to herself at the thoughts of how he would suffer, "Now then," she started cheerfully, using the same tone as Pinkie would when asking a playful question, "we have five minutes. How should we begin, I wonder?"

Calamity lurched his head forwards, snarling, blindly trying to bite the insolent mare's head off. Twilight simply teleported back a few yards as Calamity's jaws snapped over thin air. She made a tutting noise, her grin growing wider. He was still very aware of his surroundings.

'Good.'

She focused power into her horn once more. Even the use of simple magic now hurt more than anything Twilight had ever experienced before, but she swore to herself that Calamity would hurt so much more. Giant spiked chains, intertwined with a dark metal resembling barbed wire, sprang from beneath the earth, throwing themselves across the now struggling Calamity. Even blind, he knew what these were, he could sense them; his master had used them on others before. He desperately tried to escape in time, to no avail. The chains landed on opposite sides of him, burrowing back into the ground, holding him down. Then they pulled taught, accompanied by several muffled screams and a large gurgle as the spikes bit into his flesh before tearing through it. Twilight wasn't satisfied. He was still struggling, something was missing, and she now had only just over four minutes to find out what it was.

The answer came to her quickly enough. Her horn glowed brighter as she channelled energies into the chain, the black metal now beginning to make a hissing noise as it glowed, first red then white hot. Calamity made a few frantic attempts at throwing off the chains, but succeeded only in cutting further into his flesh with the now near-melted metal before collapsing and howling in pain. Several of the spines on his back were cut in half, or in the case of a few larger ones, into several pieces. Twilight paid some attention here, tightening the chains section by section, taking care not to cut off an entire bone when it could be sliced like a carrot on a chopping board.

She was almost satisfied with her work, but then another idea occurred to her, one that would truly bring Spike justice. She stopped smiling once again and focused. With a flash of magic, the bones that were still embedded into Calamity's skull began to spin in place, throwing all manner of flesh, blood and organs out through the eye sockets. She then approximated where his heart would be, if he had one at all, and slowly forced the whirring bones through his insides towards it.

Twilight squinted, focusing as the bones found their mark. At the behest of their wielder, the chains tightened around Calamity's underside, exposing the 'heart' for her to see as layers of rancid flesh were peeled away by the searing heat. Now that the insides of the beast were fully exposed, Twilight could hear the screams of those within much more clearly than before; many of them spoke in unknown tongues, apparently begging for mercy or release from their torture. She would not grant that request. Not yet. They had to suffer for the monster they constituted into to suffer. She gained no satisfaction from the knowledge of such, it was horrible, she knew it was. But she wouldn't relent, not now.

She looked back towards the 'heart'. It wasn't so much a heart as a collection of hearts, intertwined into one grotesque recreation of the organ it was supposed to resemble, almost all of them beating completely out of synch with one another. She frowned and forced the bones she had been manipulating into the collection of hearts. They still whirred around madly, and Twilight only slowed them once the inside of the organ was sure to be a hollow mess, 'Just like mine is, thanks to you...'. She smiled grimly at her own poetic imagery, then continued.

Calamity had stopped struggling, trying to minimise the pain of the searing restraints. Regardless, what he was suffering through was beyond excruciating, if not the true definition of agony itself. For the first time since his creation, Calamity wished it were possible for him to die.

"Not long left..." Twilight whined, executing the final step of her quickly formulated revenge. The bones shattered within his heart, lacing the inside with shrapnel. Some escaped from the hole that had been made upon the entry into the heart, and for the first time since the torture began, Twilight grimaced in disgust. This was going to be messy...

Celestia tried her hardest to contact Twilight, to no avail; the black veil surrounding the unicorn made it impossible for her to reach the unicorn. Ponyville was in sight now, and whilst most of it looked intact, she could see even from a distance the sheer devastation that the battle had already caused to the south west of the town, "At least it's not as bad as last time..." she whispered, her voice a strange yet familiar mixture of relief and horror as she recalled Calamity's previous rampage that had torn a continent asunder.

"This is it! The grand finale!" Twilight spat disgustedly into what was left of Calamity's 'ribcage'. She turned sharply and trotted away, putting some distance between her and the monster that now lacked about half of its original internal body mass. Once she reached what she estimated was a suitable distance she span back around and began. She looked behind her briefly, scanning for any new arrivals. Surely enough, the skyline was dominated by the regiment of fast-approaching pegasi elites that Celestia had brought with her, 'One more minute, at most...' She turned back to Calamity and began. The bone fragments embedded within him slowly began to bubble, incredible heat building up within them but not being allowed release. Barely half a minute later, the fragments were shaking violently, and Twilight knew it was time. She glared at the monster before her and spoke.

Celestia had dove ahead of the rest of her forces, trying to reach Twilight before Calamity did, but as she approached she realised that the monster wasn't posing any significant threat. He was in chains, bleeding profusely, steam rising in red swirls as his blood boiled. And there was Twilight, staring impassively with deep red eyes, "Oh no..." Celestia pushed her mighty wings to their limits, trying to reach her beloved pupil in time, closing the distance almost as fast as Spike had done less than an hour before. She landed with little grace and galloped towards Twilight, calling her name. No response. She was only metres away when she heard it. Almost a whisper, yet it seemed to echo all around her. It was undoubtedly Twilight's voice, only darker, heavier, dripping will killing intent. Celestia froze.

"This is for Spike..." Twilight spoke softly, her quiet voice echoing until it faded into silence, "... You demon spawned SON OF A BITCH!" she roared, the noise ringing in Celestia's ears. Calamity's anguished, gurgled cry was the only warning Celestia received as to what was coming, as the fragments exploded within Calamity, destroying his 'heart'. "Just as you destroyed Spike's heart, and broke my own, I've removed yours..."

The following shower of blood and gore was much larger than Twilight had originally expected. Even in her rage-fuelled state, she grimaced and braced herself against the wave of putrid innards flying towards her. She didn't get the brunt of the mess, being so far away, but she was still sprayed with blood, and small sections of tissue and bone, though she was fortunate enough not to sustain any further injuries as a result. The same could be said for the Princess, who looked between the two - but mostly at Twilight - in shock and disbelief, "Twilight, you did this?"

Twilight simply regarded her mentor passively and nodded. Celestia was about to ask why, but halted when she recalled what her pupil had said only moments ago, 'This is for Spike... just as you destroyed Spike's heart...' The realisation hit Celestia like a tonne of bricks, but she said nothing. She knew what Twilight was going through, she had experienced it herself. Losing a friend on the field of battle was traumatising, and though she had never lost a sibling this way, she could only imagine that it was much, much worse. All Celestia could do was listen as Twilight tried to explain what had happened. However, what Twilight said next wasn't what she was expecting at all.

"It's still not dead..." Surely enough, Calamity still lay there beneath the chains, inhaling and exhaling in an erratic pattern. The elites were arriving now. Accompanying the pegasi air regiment were several dozen earth pony archers and unicorn swordsmen. Whilst the archers took position around the perimeter of the now subdued herald of destruction there was a collective sigh of relief, many of them had expected to die fighting today. Between the dozens of unicorns present, opening the rift to rid Equestria of the monster would take little over a few minutes.

Twilight noticed this, however, and darted forwards, followed immediately by Celestia, "Twilight what are you doing!?" she shouted after her.

Twilight ignored her completely as she approached the unicorns. More than one visibly recoiled at her appearance, her blood-stained visage a horrific sight. She slammed her hoof into the ground, causing it to tremble madly, interrupting the rift spell as the unicorn casters toppled over, "I'M NOT FINISHED YET!" Several elites moved towards her, trying to subdue her, only to be thrown back several metres, some bleeding quite badly, lashed at by invisible tendrils. Immediately, Twilight was surrounded by elite troops, weapons raised as they mistook her for an enemy, "MOVE! NOW!" she barked at the ones blocking her line of sight. They shrunk back slightly at the sheer volume, but stood firm otherwise. Twilight advanced slowly, the sound of several arrows being nocked and swords drawn from scabbards pierced the air, "IF YOU DON'T MOVE, I SWEAR I'LL-" Twilight collapsed, now unconscious, onto the ground. A few of the braver guards shared a look then darted towards the mad pony, preparing to arrest her.

"STOP!" Celestia commanded, the glow of the spell she had used to incapacitate Twilight fading from her horn. Instantly, all present stood stock still. Celestia regained her composure before stepping towards the unconscious unicorn, "Lower your weapons, take care of the wounded and get that thing out of here at once!" she ordered, pointing a hoof at Calamity. There was a scramble of activity around her as all returned to their previous duties, asides from a few medical ponies - ashamed that they had not attended to their comrades' wounds straight away upon being attacked by the unicorn - whom now set to work patching up the bleeding elites.

Celestia sighed quietly, a deeply troubled look on her face as Twilight's features returned to normal. The armour upon her dissipated, the aura around her flashed out of existence, she slowly shrank back to her original size, and the crimson glow in her eyes faded away. Celestia called over an unoccupied medical pony and asked him to check Twilight over whilst she withdrew a cloth from his pack and began to wipe the remnants of blood from herself and her protégé. Afterwards, Celestia just sat and stared sadly at the face of her faithful student, now marred with gashes, cuts and bruises.

A cheer from behind her brought her back to her senses. She only barely caught sight of the last of the rift closing once again, a white claw disappearing through it. She sighed once more and slumped slightly. So little had been lost today in comparison with what had been lost before, "Nevertheless," she looked down at Twilight's face once again, "I fear we have already lost too much..." A single tear slid down her face and onto Twilight's. If she had been paying attention, she would have noticed her tear had merging with one of her student's before sliding slowly down Twilight's cheek and rehydrating the cracked earth below.

Author's Notes:

Edited as of 18/3/14. Quality, grammar, and wording of sentencing is now vastly better than it was. Measurements of exact distance have been replaced with approximations by the characters; both in narrative and in character dialogue. Greater description added to make it more clear exactly what was happening at some parts, especially during Calamity's torture. Character names used instead of titles in an attempt to avoid 'Lavender Unicorn Syndrome'. Rainbow Factory reference shortened in order to make it fit more appropriately.