Seize the Reins

Having stepped into a shadowy stairwell normally concealed behind his bookshelf, Stygian turned, closed the door behind himself, and was bathed in darkness. A part of him felt dirty keeping secrets from the ponies he cared about, but it couldn’t be helped. Desperate times called for desperate measures, and there was nothing - nothing he wouldn’t do to keep his friends safe.

As he slowly trotted down the spiral staircase, bathed in a cool glow emanating from his horn, he dwelled on his thoughts. He’d hoped that the Pillars and the Elements of Harmony had brought an end to the shadow magic which had once consumed him, exorcizing him of the evil he’d unwittingly unleashed so many moons ago, but he’d been wrong. Plagued by nightmares and twisted machinations, feeling his insidious alter ego gnawing at him, he’d realized all too late that he wasn’t free from his curse.

He lifted his head and looked out at the small, concealed chamber he’d crafted for himself, as his hooves touched the cobblestone floor. Many ponies would have considered the room a refuge, a safe-house built to withstand disasters, yet it hadn’t been designed to keep those within safe - it had been constructed to shield the rest of the world from what lurked within it. Reaching up and pulling back his hood, he gave a deep, shuddering sigh.

Many, many moons ago, in a bygone era, he’d been friends with some of the strongest, most capable heroes in all the land. He tried to support his comrades, offering them companionship and comfort in their times of need, but he’d been unable to impart anything meaningful to their adventures - that was until he’d discovered a forbidden tome. The curse he found, unleashing unholy power within himself, would give him what he craved, what he needed, and he’d reluctantly given in and struck a deal with unholy powers.

While he had gained strength beyond compare, there’d been a price to pay. The hex had unleashed a part of him he didn’t know he had, an evil which grew to be a threat to all Equestria, and he’d been undone by his hubris. In a grand twist of irony, having become the being he referred to as the Shadow Pony, he was ultimately responsible for the downfall of the Pillars of Harmony.

For the last several months, he’d tirelessly poured over ancient tomes and arcane texts from the Canterlot library, searching ceaselessly for a way to cure himself of his umbral blight. He’d had some success in his research, discovering similar cases of corruptive maladies documented throughout the ages, but he’d been unable to discover any one thing that may help him - fortunately, between his expertise with magic and all the notes he’d taken, his quest had borne fruit. Though he hadn’t found an answer for his problem, he’d formulated one himself.

The shadow magic afflicting him was a curse, intrinsically tied to the very fiber of his being - as such, while it would have been nearly impossible to destroy it without destroying himself, he could harness and contain it - at least he hoped he could contain it. Unfastening a button on his robe, he shrugged his shoulders and let the garment fall around his feet.

He shivered as the cool, dank air of the basement washed over his bare body. The solution he’d devised was unorthodox, bordering on the cusp of dark magic itself, so being nude for the ritual was the least of his concerns. Looking over to a table resting against the wall, seeing the heaps of leather resting on the work surface, he set his jaw and stepped forward.

Given that he couldn’t expel the evil force within him, binding it and bringing it to heel would - should resolve the issue - still, it wasn’t without risks. Not only was the technique untested, novel and to the best of his understanding unique, but there was no guarantee of success. After crossing the relatively small chamber, he lifted a harness from the table, slipped his arms through the openings, and went about securing it to his chest.

With a mirthless chuckle, he methodically fastened the straps around his legs, arms, neck, and torso. Finding the raw materials had been relatively easy, but buying them had been downright mortifying. He’d never been all that sexual, prioritizing academic pursuits over primal, lecherous urges, so forcing himself to visit, let alone purchase the leather gear from a farm shop had left him exhausted, anxious, and more than a little flustered.

He could have gone to a boutique for the purchases, but that would have been embarrassing and impractical. His restraints weren’t meant for sexual gratification - bearing that in mind, he’d gone for a practical solution. Fortunately, with all the agriculture in the area, buying leather straps and a harness had been a simple affair - unfortunately, given the odd look he got from the clerk, it was obvious he wasn’t intending to use it for hard labor.

The irony of the bindings strapped to him didn’t escape him. While there wasn’t much that riled him up, caring little for comely mares or handsome stallions, there was something about the feeling of leather against his flesh that set his heart fluttering. Perhaps his subconscious had coped with his past banishment by fetishizing it, or maybe his dubious interests had stemmed from being tied up while playing cops and robbers as a colt - regardless of the exact cause, he found it harder and harder to concentrate with every passing moment.

With the first step in the process done, Stygian moved on to the second, admittedly more difficult phase. Borne from an abundance of caution, his limbs had to be secured. The shadow magic had taken control of him before, consuming him and bending him to its will, and that wasn’t going to happen again - not this time. He ignited his horn and moved his hands behind his back as he levitated a trio of thick belts from the table.

The way he saw it, he’d rather be safe than sorry. It wasn’t until he was fully restrained, having only his legs free, that he closed his eyes. The physical bindings were only one piece of the equation - bearing that in mind, he enacted the final part of his scheme. Calling upon every ounce of his arcane might, ignoring his steadily swelling stallionhood, he uttered a single word of power.

“Carcere…”

In the blink of an eye, he felt a cold aura cascade over him. Layer upon layer of protective spellwork were cast, shielding the room, strengthening his fetters, and lastly retarding his sorcerous abilities. There would still be some risk involved with what he was going to do, but he’d be darned if he wouldn’t mitigate it as much as possible.

With a heavy sigh, he dipped his head and opened his eyes. He could scarcely move, his ability to utilize magic had been severely impaired, and it would take nothing short of a siege to break into or out of the chamber - in short, everything was as it should be. Knowing what came next gave him no comfort, even with his carefully laid guards, but that didn’t stop him. He needed to make sure his plan worked, so he did the unthinkable - he called upon the shadowy beast that resided within himself.

His lip curled, revulsion welled up within him, and a bead of anxious sweat rolled down his temple, recognizing the terrifyingly familiar sensation of the monster rousing from its slumber. He’d never summoned it intentionally, too frightened by what it could do - would do, yet that was about to change. The wild, primordial creature would be tamed, it had no choice in the matter, and he would master it no matter what.

A chillingly familiar sense of coldness welled up within him, radiating through his core as unfathomable, malign power surged through his veins. The feeling was as dreadful as it was intoxicating, causing his grimace to falter. Though he hated what he’d turned himself into, the force which he’d tied to himself, a sliver of his id reveled in the sublime strength the beast granted him.

Slowly, almost reluctantly, a dark miasma emerged from his chest and began flowing over his body. His metamorphosis wasn’t uncomfortable - if anything, it was actually quite pleasant, though that was surely by design. Shadow magic would have been employed even more rarely than it was if the process of using it was even remotely painful.

While couldn’t fully see it, only able to look down and see the front of his body, he could feel his muscles gradually expanding. He’d never been all that imposing, being thin and relatively frail even for a unicorn, but he wouldn’t stay small for long. The curse magnified his magical prowess by an order of magnitude, and it would remold the body of anypony brave or foolish enjoy to use it.

As the corruptive power crept to his back, he trembled. Each of the pony tribes had their strengths - earth ponies were powerful and hardy, unicorns wielded sorcery, and pegasi were nimble masters of the skies. Aside from alicorns, legendary creatures who held traits of all ponykind, there were none who could boast about having the abilities of all three races - none but him.

His heart thundered in his bosom, his breaths grew heavy, and his stallionhood excitedly twitched in the cool air, while a pair of midnight-black wings languidly formed on his back. He’d calculated for the additional appendages, the harness he bore keeping the limbs pinned against him, though they struggled and attempted to break free. Twisting in place, pawing at his bonds with his fingers, he shook his head and cursed.

Free me…

“No!” he growled, shaking his head.

That was not a request…

His body rebelled against him, compelling him to take a small step forward, but he resisted. In hindsight, he should have bound his legs - nevertheless, he was still in control and he’d taken contingencies. The floor around him flared to life, concentric circles of runes illuminating the gloom, and he froze. If the Shadow Pony thought he was going to win this fight easily, it was wrong.

A frigidness flowed up his face and to his jaw while an ominous laughter rang in his head. The beast was many things, but it was no fool. Once the transformation was complete, he’d be reduced to a spectator, beholden to the monster’s will - that’s how it normally went. If his preparations and research had amounted to anything, he’d retain control of himself even after the magic was fully unleashed.

Give in…

Twisting and turning, gnashing his teeth, Stygian grunted. With every second that passed, the struggle for dominance grew more savage. Locked in battle of wills, pitting himself against the monster inside him, he fought with everything he had. As phenomenal as he felt, wracked with bliss and the knowledge that he could take on the world, he wouldn’t succumb.

The belts and straps around him grew taut, straining to contain his ever-increasing mass, but they held firm. Between the worldly and metaphysical restraints, every part of him was restrained - every part but one. Pre-cum dewed the broad tip of his stallionhood, leaking to the stones beneath him, while the onslaught of rapture mounted.

Though he knew what was coming, that the last phase of his metamorphosis was upon him, nothing could or would ever prepare him for it. He threw his head back and gasped as darkness coursed over his muzzle and into his maw. In that moment, opening his eyes and seeing the world in a new, different light, he was brought to the brink.

Yes…

“Shut - Mmmph - up!” he blared. His tongue grazed what had once been blunt teeth, running against smooth, razor sharp fangs, while the battle ensued. “I won’t let you win!”

You will…

Before he could say a thing, faster than he could think, his wings snapped free. Wheeling around and turning his head, seeing the appendages unfurl behind him, he was overwhelmed with the urge to escape, to soar up the stairs, though his home, and out into the world, but he wouldn’t - couldn’t. Clenching his jaw, he clamped his eyes shut.

Submit…

“Never,” he seethed.

Looking down at himself, seeing his stallionhood drooling uncontrollably, he swallowed hard. His torment would have been hard enough to endure by itself, but the blinding arousal of his metamorphosis was maddening. As he fixated on his endowment, marveling at how much longer and thicker it was than normal, the voice in his head chuckled.

The beast knew how torturous it was, that he was so hard that it actually hurt, and it attacked that weakness without remorse. His length throbbed and swelled, growing with every beat of his heart. While he was far from a prideful pony, the sight of his massive endowment tipped the scales against him.

Go ahead…

Twisting his hands behind his back, he flexed his arms. Though he barely realized what he was doing, several of the leather belts around him broke instantly. The sound of tearing fabric, paired with the Shadow Pony’s delighted laughter, brought him back to his senses. As tempted as he was to play with himself, giving the beast even the slightest bit of leeway would result in nothing but disaster.

His little experiment had been successful, he’d managed to keep control of himself after the transformation was complete, yet the toll it took was heavy. The crushing weight of his longings, the siren’s song to wreak havoc in the world, was almost too much to bear. Swinging his arms forward and before his chest, he grabbed his wrists to keep himself steady.

Go on…

Lowering one trembling hand, he brought his digits to within a hair’s breadth of his loins. The heat of his equipment bathed his fingers, doing nothing to bolster his inhibitions. It had been weeks - no, months since he’d gotten off, too preoccupied with his studies and helping his friends, so nopony would blame him if he got just a little relief ~ right? His eyes shot down to the protective sigils, ensuring they showed no signs of weakening, as his resolve began to crumble.

He cautiously wrapped his fingers around the base of his shaft, gave a contented sigh, and smiled. It had been too long since he’d blown off a bit of steam, almost forgetting how good it felt getting any sort of amorous attention. Relishing the immense weight of his shaft, barely able to touch his thumb and middle finger together, he drew his hand up toward the tip of his length.

As his digits glided over the sensitive area beneath his cock-head, he bit his bottom lip. It may have been his imagination, but his stallionhood felt much more sensitive than usual. Inspired, his concerns overshadowed by the carnal pleasure of touching himself, he shut his eyes and fixated on his bliss.

His bindings, both earthly and incorporeal, fanned the growing flames of his desires. He’d never given much thought to the sexual side of his metamorphosis, having always been focused on grander, typically more chaotic pursuits, so he was stunned to discover just how phenomenal simply jacking himself off was. Bucking his hips, he brought his free hand down to his shaft.

The sheer enormity of his endowment was staggering. His stallionhood was so long and thick that there was room to spare while using both hands to stroke himself, although it was only part of the package. Swinging beneath him, heavy with seed, were a pair of weighty, cum-laiden balls that would put even the most virile stud to shame.

Seconds stretched into minutes and longer still, as he gradually lost himself to the moment. He’d had no intention of doing something so scandalous, especially under such dire circumstances, but he took solace that he was still trapped within the small subterranean tomb - or so he thought. A low, sonorous snarl crept to his ears, snapping him from his stupor, but it was too late.

Yes…

Just like that, he’d lost. His composure was sundered, weakened by sins of the flesh, and there was nothing he could do. Though he had no control over it, his lips curled over a triumphant, fanged grin. He screamed, enraged that the beast had taken control, yet the only sound to escape him was one of triumphant laughter.

“Relax and enjoy it,” he said, his voice not his own. “I know how much you’ve been wanting this…”

Hunching forward, ropes of saliva hanging from his chin, he fucked into his hands. A prisoner in his own body, but with his senses intact, he suffered through a blissful, horrifying haze. If there was one saving grace, it was that his bonds held firm and kept him from escaping - still, there was no guarantee that his fetters wouldn’t fail at any given second.

What should have been an enjoyable experience was twisted - perverted by the creature controlling him. He railed against it, telling himself that he should take no pleasure from his defeat, but it was no use. To say the experience was anything but heavenly would be an outright lie, so heady were the waves of rapture consuming him.

He and the Shadow Pony were two sides of a coin, linked on a fundamental level, and the depraved masturbation was exhilarating for the both of them. As much as he hated himself for it, the sensory assault was more than he could handle. The leather wrapped around his body, the feeling of his gargantuan endowment in his hands, the hedonistic bliss of self-consummation - each aspect sang a siren’s song to his long-suppressed desires.

Harder and harder, faster and faster, he thrust into his twofold grip while grunting to himself. Where once a timid, scholarly unicorn had stood, now was a nightmarish animal without the slightest shred of reservations. With his pleasure steadily mounting, his resistance to the Shadow Pony’s takeover waned. He was so close, so very close to release, that the baser parts of his mind overtook his higher functions.

Stretching on for what felt like a small eternity, long enough to push his consciousness to the breaking point, his masturbation drove him to the brink of madness - mercifully for him, moments before he begged the Shadow Pony to finish him off, he was granted release. With a bestial roar, his bellow reverberating throughout the chamber, his wish was granted. Seed gushed from his pulsing length, erupting out the flared head to paint the floor and nearby wall with his essence.

The climax was singular, by no small margin the most powerful he’d ever endured, and it brought with it some clarity of mind. His strength fled from him, he heaved air into his chest, and he nearly collapsed to the floor as the Shadow Pony relinquished its hold upon him. To say he felt relief would be an egregious understatement, yet the experience had left him drained in more ways than one.

He wearily peered down at himself, finding his lithe, grey-furred body just as it had been, and shook his head. While his experiment had been a success, keeping him from doing any harm to anypony, the victory was pyrrhic. Thoughtlessly pushing himself up and shambling to the stairs, cum splattered on his hooves and lower legs, he steeled his resolve. Next time, because there would be a next time, he’d be sure to tighten his bindings just a bit more…