"You deserve what you had coming to you!" Luka cried, inexpertly triggering the stone.
Mike felt the all-over tingle of transformation overcome him again, and he groaned aloud. His voice cracked and squeaked midway through, as his body compressed and and shifted into its new form. The fit, if soft physique of a burgeoning wizard rapidly gave way to that of a spindly boy, barely over 5 foot tall, seemingly right in the most awkward phase between little boy and teen. Suddenly clumsy, his hands and feet too big for his skinny body, he stumbled. His handsome face shifted, ears sticking out to the sides, nose a little too large, a little too round, his front teeth sticking out notably, the rest of his teeth crooked and gappy. Freckles spotted across his nose and cheeks, as well as his suddenly bare chest and shoulders, and his hair grew out into a shaggy, coppery mess.
Mika the stableboy was back, or at least one version of him. The undernourished, unwashed 14-year-old's eyes seemed to dim as all his wizardly training evaporated, along with a good number of his IQ points. His alarmed expression slowly gave way to a dim-witted smile. His former robes, reduced to a tattered loincloth, stirred and slipped aside as an absurd 7 inches of male equipment rose to attention. The former wizard played with it idly, too simpleminded now to realize he shouldn't.
"Oh!" Luka cried out. "I didn't- I wasn't-" he stammered, as he dropped the stone.
" 'scuse me," Mika drawled, apparently noticing people were nearby for the first time. "Can y'all show me how ta get back to my master's stables? He'll be sore if I'm missed."
The group looked on in shock.