The warrior's footfalls echoed on the cobbles. His breath steamed in the cold, frosty air. He heard the frantic movement of assailants in the shadowed alley shuffling to surround him.
The warrior laughed. It was a bitter, dry laugh. "It won't do you any good. I feel no pain. Prepare to meet Balor."
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.