The concoction burned in the pit of Hiro's stomach, but he endured. He could feel the burn spreading throughout his body, his veins afire, carrying energy to every sinew and tendon, every inch of his body humming with power. He groaned softly, as his body slowly began to grow. He became a little taller, and his frame broadened, as his muscles slowly began to thicken. His pants rode up his legs, baring his ankles, even as his swelling thighs filled the pant legs, until they were tight like spandex around his mighty quads. His shirt similarly rose, revealing tight, hard abs, while his thickening chest, shoulders, and back stretched the top of the shirt tight. His arms ballooned, filling with thick, juicy muscle. The sleeves of his tee shirt were unable to contain them, and split along the seams, revealing big, veiny bulges of power.
Hiro moaned, reaching for his crotch, cupping the swelling cock and balls trapped beneath the fabric of his pants, bulging outward obscenely, straining his zipper.
Mr. Yaun just smiled. "Now you have what you want," he explained.
Hiro looked at himself in a mirror. He was taller and sexier, with big, powerful muscles, and a big, horny cock. He was a freak, like Guy (if not quite as big.) Was this what he wanted? It was, he realized.