The particularly nasty Wordstone placed in Jon's possession was the Scheming Wordstone.
The bearer of this stone would be transformed to suit the first three adjectives they utter while holding the stone, within a day of speaking the third.
Once the victim is cursed, the stone would engineer one or more (even fantastical) events "“ a surprise makeover, facilitating a lab accident, providing mislabeled medication, a chemical spill, an alien abduction, a poorly phrased wish "“ to achieve the desired transformation within 24 hours.
The events are but a deception - both to integrate the victim's new form into reality and society, and to hide the real source of the victim's woes.
Later, should the victim of the curse no longer resemble the three descriptive elements thrust upon themselves (by any means), they will be free of the curse "“ and free to be cursed again...