A king so vile and treacherous was cursed many centuries ago to forever roam the earth. He is now a serf of earths will and shall be anywhere needed to stop the destruction of earths its bueatiful landscapes and creatures.
An alchemist enchanted his equipment to produce even more powerful alchemical compounds, potions and the like. Unfortunately, it is not well-known that he had different sets of equipment for different processes: If the wrong set of gear is used, the result will invariably fail to function. It's not a cursed item, just something that's hard to figure out.