Nathan could feel it in his bones… He felt it in every inch of his skin, and even in every follicle of hair on his body. There was a heat within him like that of sunshine. It radiated all around him, pulsing and pushing out of his core.

He felt this during his first transformation, but it wasn’t this sustained and persistent. The energy that brought forth his animal nature was strong and acute before, but now it seemed to never stop! Something was happening deep within him that very few had ever experienced. And he had no idea why it was happening to him.

The satyrs and creatures that shared the cavernous space with him tended to him, making sure he was okay as he twisted and writhed with the intense reaction. Whenever he felt a burst of pain or pleasure, a handsome, horned figure would emerge, holding him down and keeping him still; easing him through the rush of power that coursed through his body.

He couldn’t tell how long he’d been there. Without seeing the sky or the entrance to the cave, he couldn’t see day or night pass. He slipped in and out of consciousness following his intense breeding from the massive minotaur, reeling from the physical and mental exhaustion of such an encounter.

Even as he would wake from his slumber, his hunger or thirst would be satiated by the cum of his immortal custodians. Some would feed him their seed off their finger, running it over his tongue and lips as he would stir up from sleep. Others would present their huge Theban cocks for him to suck and feed from. As their fluids filled him, all his needs seemed to be met, quieting his aching stomach and parched throat; giving him the strength to soldier on through his transformative state.

It was after a few days that Nathan felt his internal heat move from his entire body to his loins. He needed to fuck more than he needed to eat or sleep. He was aching for it, clawing at the walls and begging for the satyrs to satisfy his hunger. The horned men looked at each other, seemingly understanding what this meant and what needed to be done.

The satyrs held the horny boy down, keeping him from leaping onto them in a manic rush. They stroked their cocks, getting them hard and ready for another passionate fuck.

Nathan smiled and his eyes widened as they brought their shafts to his mouth. He could smell their musky nuts and shaft. As one filled his mouth, he breathed deep, inhaling the satyr’s scent, feeling his nipples harden and his hole tighten with excitement. He couldn’t remember needing anything so bad in his life. As he swallowed down every throbbing inch of one, he could feel the sliding of another between his cheeks, teasing his hole with their raw cock!

His heart raced, not sure where to put his focus. More satyrs closed in, throwing their cocks in his face until he was surrounded by their enormous members, all looking equally appetizing and aiming for his face. He moved back and forth from one to the other, trying to take them all and never wanting even a second of time to pass as he shifted from one shaft to another.

Nathan moved himself on all fours, feeling his animal instincts rise to the surface; presenting himself to be fucked. The satyrs smiled, pleased to see such eagerness from their guest. The non-stop diet of their seed clearly had the impact they wanted, seeing his body primed and ready for all they could give. Nathan knew he was acting differently and he felt stronger than ever before, but he didn’t care. He saw a cave full of the most beautiful, magical creatures he’d ever seen, and he wanted to be filled with their manhood.

Nathan took another massive cock into his mouth, worshipping it as the satyr began to slide his slippery meat further between his cheeks. As wild as he was, Nathan managed to time his breathing and relaxation such that the breeding satyr was able to plunge himself deep into his hole without making the horny boy cease his oral service. He felt himself get fucked from both sides, filling his hole and mouth with thick, veiny cocks as he moaned in delight. He could have been locked in that position for hours and still would have begged for more.

The fucking didn’t last long, however. Almost as soon as his hole was opened, the satyr pulled out, leaving him aching for the vacancy between his legs. He whimpered, desperate for more…

He looked back, hoping to see another figure take the place of his top. Instead, he saw Bishop, the man who had brought him there, approaching him with a rope and a devilish look. Nathan began to feel concerned, unsure what was happening… He wanted to fuck, but he also wanted to flee. His baser instincts seemed to mute his higher thought processes and he jumped up as if to run. Bishop stopped him with the help of his fellow satyrs, holding him down as he tied a rope around his body.

“Shhh, it’s okay, it’s okay,” Bishop reassured him, trying to calm the frightened beast boy. The rope passed over his chest and shoulders, tying him up like a pet in a harness. “It’s going to be okay.”

Nathan calmed down, soothed by Bishop’s voice and touch, but also his caring and loving look. Nathan could tell Bishop was going to protect him and keep him safe. Despite the strange circumstances of the last several days, Bishop was the one thing Nathan could trust to be there for him.

With the rope harness secured, Bishop helped Nathan up to his feet, calming him through his involuntary spasms. Bishop couldn’t deny how good he looked, however. Seeing his wild, goat-boy Promethean desperate for satyr cock was more than he could handle. His hands stroked his body, feeling Nathan’s new found strength and power.

Having been freshly used and Nathan was put at ease, Bishop walked him from the chamber he’d stayed in since his arrival, into a deeper part of the cave.

Nathan frantically felt his hunger build without the sensation of the satyr’s meat inside his body. Bishop and another satyr kept him moving, keeping him from being distracted by his amorous state.

Nathan felt like he’d walked for about half an hour when they came to a wide, bright expanse deep in the earth. They walked into a large clearing, light as if by bright moonlight. Surrounding the perimeter were trees and rocks. Nathan was in awe that such a world could exist while being kept secret from the world outside. Ages passed and civilizations had risen and fallen, but this tranquil place had remained untouched!

Coming towards the center of the room, the satyr men led Nathan to a circular alter, bathed in the otherworldly light of the tiny hidden underground forest.

Nathan continued toward it, following the lead of his guides. He wasn’t sure what to expect, but he trusted Bishop completely. The older man helped Nathan to the large, bowl-shaped structure, watching him as he observed its size and depth. Nathan understood that the altar was for him; to continue his journey, he had to receive the ultimate gift of the immortals.

Nathan’s cock throbbed with desire, still charged with the fuel from their loads. Nevertheless, he followed their lead, lowering himself into the basin as he waited for the next challenge he would endure.

As he laid on the circular platform, he gazed at the trees, seeing them move delicately in the subtle subterranean breeze. Shadows danced on trunks, disappearing into the surrounding darkness, creating a sense of endless depth that mystified his senses… And then, to his surprise, he saw one of the shadows move forward, breaking from the ranks of trees and coming into the light.

The figure was that of a large, muscular man, standing roughly seven feet tall on four large legs. A dense, equine frame carried him, connected at his defined stomach. As he got closer, Nathan could see this was a mighty centaur, majestically coated in brown, satin fur. He moved with grace and a regal presence…

Nathan’s cock grew hard, aroused by the powerful figure. He stepped forward, his hooves making soft sounds against the packed ground. His steps were muffled by dirt and leaves, but still indicated the centaur’s weight and strength.

The horse-figured man came closer, nodding to his satyr companions as they made their way back through the tunnel from which they’d come, leaving Nathan to his pleasure.

The centaur reached for Nathan’s cock, feeling a drip of pre-cum, and bringing it slowly to his mouth. Nathan could see he was strikingly handsome, as if he was some type of fairytale prince. He was overwhelmed by his size and power! Nathan felt himself falling limp, the idea of a living centaur proving to be more than he could handle.

The centaur lifted him up, carrying him in his big arms, feeling the little faunlet yield to him completely.

The centaur lowered Nathan down on his back, lifting his legs up and running his hands on his buttocks. The boy’s hole was still warmed up and wet from earlier, clearly having been primed by the satyrs who had brought him there.

Nathan closed his eyes, enjoying the attention and care, but his comfort was quickly cut short as he felt the most intense penetration of his life.

It came to him at first like a massive pressure on his hole. The horse cock worked up against him, pressing his buttocks inward. It was a push like that of a bike seat, seemingly unable to break through his narrow hole, but compressing the flesh around it.

Nathan’s heart raced, unsure if he could withstand anything like what was about to happen, but desperate to feel himself open up and take it. He looked up at the equine giant, both scared and excited all at once. The beast gave him a look of adoration, as if seeing deep into his soul and understanding just how special and unique Nathan was.

Nathan similarly understood that this centaur was like Bishop — caring and considerate. He knew the centaur would never hurt him… And in that moment, he felt his body relax as the monstrous horse cock slid inside him.

It filled him deep inside his body unlike anything he’d ever known. Depths of his core were accessed that he never knew existed as the centaur’s thick meat worked slowly into him. Nathan’s eyes went wide and he let out a gasp as if the member was pushing the very air from his lungs!

It hurt initially, making Nathan wince and grit his teeth, as he tried to withstand the shock and force of what he felt. Within moments, his muscles quaked and quivered, easing up their deep held tension until his hole had fully wrapped around the massive shaft.

As Nathan fully submitted to him, the centaur used his strong, powerful legs to thrust himself deeper into him. Nathan could feel the giant’s balls swinging against him. They had weight that was beyond impressive, making Nathan horny with the thought of how they would soon unload into him.

The centaur’s fucking was so intense, Nathan could swear his cock worked up against his spine. He’d let out a yelp, feeling the sting of the cock, only to have the centaur pause and look to Nathan for assurance. Nathan didn’t know if it would hurt again, but he would do anything to keep it from stopping!

Nathan felt himself lose sense of gravity as the fucking intensified. All of his senses were focused towards his hole, breaking from reality and thinking solely of the powerful penetration he was enduring. He didn’t want anything more than to feel the force of the centaur’s climax. As the centaur got closer, his body began to tremble and shake, transforming from the horse-like body he’d arrived in to that of a more common man.

Nathan watched as the man’s hind legs disappeared into his hips, all while maintaining the pleasure-inducing rhythm of an expert fuck. He felt the man’s cock shift in him as well, picking up speed and force as it worked its way down to a more mortal size. Even with the transformation from centaur to man, his cock was still larger than most as it banged into Nathan’s prostate and caused his cock to seep pre-cum.

With a few more powerful thrusts, the centaur-man poured out his seed deep into Nathan’s ass, filling it beyond capacity. Nathan felt the centaur’s fluids as they poured out of him as he thrusted back. The surge of semen into his anal cavity was so intense that it almost forced Nathan to cum at that moment… And were it not for the diet of centaur cum coursing through his body, he very well may have!

Nathan looked up at his handsome top, exhilarated and ready for more. As his senses came back to him, he could see more figures around them in the background. He’d taken them to be trees during his breeding, but now he could see they were actually a group of handsome men; standing around and stroking their cocks. Before the centaur could withdraw his cock completely, he saw them all begin to whinny and jump as they transformed into centaurs themselves!

Nathan felt his top pull out, causing a good deal of cum to leave his body. As if their mission was to keep him full, another centaur came in from behind and pushed his cock deep into Nathan’s body.

One after another, each centaur bred Nathan again and again. As Nathan took the loads of several more beasts, he didn’t know how long he could keep up, but he was determined to last as long as possible!

As the centaurs sensed the boy nearing his limits, they gave him the chance to lie down in the basin. As he caught his breath, they circled around him, continuing to stroke their cocks. Nathan took his own meat into his hand, stroking it and feeling himself get aroused as they all towered above him…

Suddenly, without warning and in perfect synch, every centaur let out a loud neigh as their cocks poured out gallons upon gallons of their semen onto him. Nathan was drenched in a warm, thick flood of their seed; filling up the basin of the altar around him. As he laid in a bath of white liquid, he felt the familiar tingle in his skin that excited his body… It felt like absolute heaven!