The Black Pudding's Corrosive Form contains the following text:
Any nonmagical weapon made of metal or wood that hits the pudding corrodes. After dealing damage, the weapon takes a permanent and cumulative -1 penalty to damage rolls. If its penalty drops to -5, the weapon is destroyed.
The Mending cantrip is as follows:
This spell repairs a single break or tear in an object you touch, such as a broken key, a torn cloak, or a leaking wineskin. As long as the break or tear is no longer than 1 foot in any dimension, you mend it, leaving no trace of the former damage.
So a few interconnected questions culminating in how does Mending interact with corroded weapons:
- Since corrosion represents material that is worn away, not a break or tear, does Mending technically even work on it?
- Would Mending mitigate the permanent and cumulative -1 penalties to damage rolls?
- Since mending heals a single break or tear, does it work on multiple consecutive breaks or tears if used back-to-back-to-back-to-back?