Erik pulled his cock from the slick ruins of the boy's asshole, his cock soaked from his own cum and flecks of Ed's blood. The boy himself had passed out after the fourth charge, his own release running down the side of the bench. His hole hung open, the insides pulsing, and Erik took a moment to reach a large hand inside, pressing against the pulsing warmth and pulling out a whole handful of his own cum. More was gushing down Ed's thighs but Erik barely noticed, far too focused on slathering his shaft with the makeshift lube and jerking it back to hardness. The unnatural increase in testosterone Ed had injected had amped Erik's sex drive up to inhuman levels, making it impossible for him to stay soft for more than an hour without a warm hole to pound.
Mid-stroke the locker room door opened, revealing one of Erik's teammates, Darren. Darren was a year older than Erik and wildly popular, his Greek features and chiseled abs a hit with anyone old enough to be turned on. He'd even begun rocking a short beard, a sign of the strong Mediterranean blood in his veins.
Darren ground to a halt at the sight of Erik, obviously not recognizing the massive hairy brute jacking off in the middle of the locker room. His eyes slid to Ed and widened as he realized what was going on. However, that moment was a moment too long because by then Erik had clamped a hand around Darren's forearm, pinning him down as he tore the other boy's shirt off in one swift motion, revealing his cut abs and pecs, a faint dusting of black curls stretching from nipple to nipple.
"W-Who are you?" Darren demanded, his voice surprisingly strong considering his situation.
Erik took some of the cum smeared on his cock and wiped it across Darren's face, enjoying the disgusted look his teammate gave him at the heavy musk. "What," he replied, "you don't recognize your MVP?"
The panic was replaced with shock as Darren realized what he was saying. "Erik? But I don't--how could--"
Rather than answer the questions Erik turned the boy around, shoving his face into the cold tile as he yanked Darren's pants to the ground, revealing a tanned ass with a sprinkling of dark curls down the crack. His cock was at full attention already, still smeared with his and Ed's juices, so, ignoring Darren's screams and pleas, he pressed the enormous head of his cock to the boy's hole and pushed right in.
Although not as tight as Ed, Darren's hole was bliss and Erik began thrusting with all his might, jamming his former friend's face into the wall to muffle his whining. Their upright position gave him even more momentum and with each thrust he actually lifted Darren off his feet, driving his shaft into the boy's intestines with such force he couldn't breathe. He pulled Darren back against his chest, enjoying the feel of it against his hairy muscles, and it was in that position that he pumped a scalding-hot load into the boy's rectum.
Erik was midway through his second orgasm when he realized that something was happening to Darren. It started at his ass--amidst the cum gushing from his hole, Erik saw the black curls begin to multiply, spilling over Darren's crack and rising all the way to the base of his back. He pulled out just far enough to flip Darren onto his back, allowing him an up-close view of the transformation.
The hair spread up Darren's taint, thickening the hair on his thighs and causing his pubes to erupt until his cock was almost invisible in their wild forest. It then surged upwards, covering not just his abs but his entire midsection with hair, connecting to his armpits and then rising over his shoulders and down his arms. His thin beard connected to his mass of chest hair, crawling up his cheekbones and filling in until it was as thick as a real man's.
Next came the muscle, and it was the part that Erik enjoyed the most. He could actually feel it as Darren's glutes tightened and strengthened and he swore as the pressure stirred another orgasm from his balls. Darren had always been what qualified as a "pretty boy" but now his shoulders were broadening, pecs growing to bursting, and there was no way Darren could pass as anything less than 25. His cock had grown with the rest of them, not as long as Erik's but thick and hairy as the rest of him.
However, the most notable change was that Darren was no longer screaming. No, now he was moaning, biting his lip and gasping as Erik's cock struck deep inside him. His wrists had grown too thick for Erik to hold in a single hand but it didn't matter as Darren grabbed his shoulders, mumbled pleas spilling from his lips as he clenched tight, literally begging to be fucked harder.
So Erik obliged.
"We're gonna make more," he growled as he pulled out, wiping off his now-soft cock in a single motion. "We're gonna make everyone like us. Our whole team. Everyone." Darren grinned and nodded in agreement so Erik smirked in reply. "Feel free to thank him," he said, gesturing towards Ed's limp form.