(I think this is a very funny idea, but I wanted to change the rules a bit...)
Jon brandished the wishing stone, unaware that he was in fact holding the Mighty Morphin Stone, which had an entirely own set of rules.
The stone grants wishes like Jon's old stone, however anyone who makes a wish with the stone will transform into a sentai hero themed either to the content of the wish or to something normally associated with it.
The wish will also grant the sentai hero will also gain a single super power and a colourful special weapon - both themed to the subject of the wish. While they may not immediately know what these can do, the hero will find them very useful indeed, because the wish will also create a thematic villainous monster or evil ranger as their adversary!
The only way to return to normalcy is for the hero to vanquish the evil-doer. If they can't save the day, then the hero can't save themselves from a lifelong career as a sentai ranger.
Additional wishes will only add to and mutate the sentai's original theme, and each wish will also provide an extra power, weapon and adversary for the ranger's catalogue. However the hero's thematic alterations won't vanish piecemeal. He or she will retain every one until all their enemies have been defeated.
Had Jon known any of this, he would certainly have thought twice about what he said next.
"I wish..."
