Enfeeble

You target a man-made surface or item constructed from stone or metal. While your concentration remains, the object becomes slightly brittle or malleable (your choice) to you. If used on something held or worn by another creature, they can make a CON Save against your spell save DC or suffer a minus two to either their Armor Class (if it's armor) or their attack rolls (if it's a weapon) for the concentration duration. Other items that aren't weapons or armor simply suffer the previous brittling/softening.