They gain more power than their wildest wet dreams

As Mary, Sara, Anne, and Arthur stood on the platform for the test, the machine began to hum as it changed their bodies. They had arranged themselves in a tight circle facing inwards towards one another, with only a foot from the platforms edge on each end. For a few seconds the teens remained still as they tried to feel the impacts of their biology being altered kick in. Soon enough as Anne had envisioned in her design, they were suddenly hit with a feeling of euphoria that would have knocked out mere mortals. But this was only the beginning of the process.

For all their power the one thing that limited for these teens was a sense of moderation. The test was only meant to last but a minute to gauge the effectiveness of the machine. But with all four teens in the throes of ecstasy there was nothing to stop the machine as it continued to transform them. Anne had installed a monitor with a graph to index their relative intake of the mysterious cosmic energy. It had doubled from a baseline of 100% to 200% in the first minute and then continued doubling. It did not take long from there for their bodies to be affected as well.

The girls seemed to grow in every direction. Their heights kept adding inches while their waistlines stayed trim. Their breasts went from dominating their chests to becoming forces in their own right as they grew beyond any mortals arm-span. Beneath their still perky breasts their fit bodies found new ways and places to add muscle to their titanic growing frames. Fondling their own bodies the girls could only find skin smoother than silk and stronger than steel. For Arthur it seemed that his cock was the main beneficiary of the process, as its' erect form closed the several foot gap between him and Mary. His body remained ripped but only gained a token foot or so in height. However he did not feel any disappointment, as standing before him were 3 uber-goddesses growing hornier by the second.

But before the teens outgrew the platform, the machine suddenly suffered a short-circuit, as the cosmic energy surrounding the teens had overwhelmed the circuitry. The hum disappeared as the sounds of the four's groans of pleasure became the only noise in the room. The platform had deformed under their feet and now Mary, Sara, and Anne had reached a massive ten feet in height compared to the inhuman eight feet Arthur had. Nothing was said but it was clear what would happen next.