Phoenix Stone

The stone he put in its place looked no different say for yellow specks embedded, it was in fact the "Phoenix Stone", an item that does grant wishes and work like the regular stone but every five hours or ten wishes the stone would disintegrate and reform in a random location (like a phoenix being reborn from it's own ashes) with in it's range at the point of disintegration, Furthermore after the stone reforms it can undo wishes made by itself before the last disintegration.