Rusting Grasp

Your touch carries the consuming decay of nature's reclaiming force. Choose one ferrous creature or object you can touch. A ferrous creature, or a ferrous object held or worn by a creature, requires you to make a melee spell attack against the target, affecting it on a hit.   A non-supernatural ferrous object you touch instantly corrodes and crumbles to reddish flakes. If the object is too large to destroy entirely, a 3-foot Radius section of it is affected instead. Weapons are destroyed in this way, and armor affected loses 1d6 from its AC. Armor that is reduced to 10 AC in this way is destroyed.   A supernatural item resists the corrosion. Make an ability check using your spellcasting ability. The DC equals 10 + the item's rarity tier: 10 for common or uncommon, 15 for rare or very rare, and 25 for legendary.   A ferrous creature you touch takes 6d6 acid damage. If the target is a creature with natural armor or body parts made of metal, you have Advantage on the attack roll.
 

Level: Drd 4 Components: V, S, DF Casting Time: 1 standard action Range: Touch Target: One nonmagical ferrous object (or the volume of the object within 3 ft. of the touched point) or one ferrous creature Duration: See text Saving Throw: None Spell Resistance: No Any iron or iron alloy item you touch becomes instantaneously rusted, pitted, and worthless, effectively destroyed. If the item is so large that it cannot fit within a 3-foot radius a 3-foot-radius volume of the metal is rusted and destroyed. Magic items made of metal are immune to this spell.   You may employ rusting grasp in combat with a successful melee touch attack. Rusting grasp used in this way instantaneously destroys 1d6 points of Armor Class gained from metal armor (to the maximum amount of protection the armor offered) through corrosion.   Weapons in use by an opponent targeted by the spell are more difficult to grasp. You must succeed on a melee touch attack against the weapon. A metal weapon that is hit is destroyed.   Note: Striking at an opponent’s weapon provokes an attack of opportunity. Also, you must touch the weapon and not the other way around.   Against a ferrous creature, rusting grasp instantaneously deals 3d6 points of damage +1 per caster level (maximum +15) per successful attack. The spell lasts for 1 round per level, and you can make one melee touch attack per round.