Any nonmagial metal item you touch becomes instantaneously rusts, pitted and worthless, effectively destroyed. Make a melee spell attack against a creature or nonmagical object no greater than 3 feet in any dimension. If the target was an object, on a hit all metal components of that object are instantly destroyed.
If the target was a creature, on a hit choose either a metal shield or weapon it is wielding, or metal armor it is wearing. That item takes a permanent and cumulative -1 penalty to the AC it offers. The armor is destroyed when it has an AC of 10 or a shield that drops to a +0 bonus is destroyed. Metal weapons in use by an opponent targeted by this spell are more difficult to grasp. If you hit the weapon with this attack (not the other way around) the metal weapon takes a permanent and cumulative -1 penalty to damage rolls. If its penalty drops to -5, the weapon is destroyed. Use the AC of the creature wielding the weapon to determine the AC of the weapon. Using this spell to damage weapons provokes an opportunity attack.
