Agnes' Corroding Mist

“Every blacksmith and worker’s worst enemy, now in the palm of your hand!

(Store in a non-metal container, keep away from all metal until ready to use. If used in a poorly- ventilated area, stand back. This substance does not know the difference between the target metal and your metal, nor does it care.)”

- Excerpt from the label of one of Agnes Rosenthal’s potions

Holding the bottle with your teeth, you spray the mixture inside out, creating a cloud of metal-destroying vapor. Choose a point within range. A reddish-brown cloud appears there, taking up a 20-foot sphere which spreads around corners. It persists for the duration of the spell or until a strong wind disperses it. You choose whether the cloud stays in place or moves 10 feet directly away from where you cast it on each of your turns. Any metal inside this cloud is rapidly corroded and rusted. Nonmagical metal objects that aren’t being worn or carried that enter the cloud will rapidly lose durability, and if they spend a certain amount of turns within the cloud, they are destroyed. This amount changes depending on the size of the object. If a creature wearing or holding nonmagical metal objects enters the cloud for the first time on its turn, it must make a Dexterity saving throw or have any metal items it is carrying rusted, with armor taking a -2 penalty to its AC on a failed save, or -1 on a success, and weapons being brought down one die size on a failed save (e.g.; 1d12 to 1d10), or no effect on a success. Armor that is reduced to an AC of 10 is destroyed, and a weapon that would do less than 1d4 damage is destroyed.