The dispelling device will likely be one of the overarching plots for chapters to come. Sure, the second king had it, but the third took it to study it further. But then the fourth stole it for themselves due to greed. The fifth took it back and held it so no one would hold its awesome power. The sixth then got it to cont-- you see where I'm going.
If the joke follows through, its been a paperweight on the current king's desk she uses sometimes to open bottles and can lids.