Rust Harbinger

Your specialization and training grant you the following spells. You know the following spells and they do not count towards the number of spells you can prepare.

You learn to produce and use the enemy of all metal: Acid. You are proficient with Alchemist Supplies. If you already have this proficiency, you gain proficiency with one other type of Artisan's Tool of your choice.

You are incompatible with metal products. You cannot wear metal armor or wield metal weapons. If you are in contact with either, the equipment will deteriorate in one hour of continuous contact, becoming useless scraps.

You learn the spell Find Familiar to call upon one of your trusted allies. You can cast this spell once per long rest without expending a spell slot and when the spell is cast this way you can summon a Rust Monster.

You surround yourself in a thin coating of the dust produced by the Rust Monster’s antennae. Any non magical weapon made of metal that hits you 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. Non magical ammunition made of metal that hits you is destroyed after dealing damage.

You coat a non metallic weapon with dust produced by the Rust Monster’s antennae. You can maintain one such weapon at a time. If you coat another weapon the first weapon becomes a normal weapon. The weapon corrodes non magical ferrous metal objects you attack. If the object isn't being worn or carried, the touch destroys a 1-ft cube of it.

If the object is being worn or carried by a creature, the creature can make a DEX saving throw DC equal to your spell save DC to avoid the effect, but still take the weapon’s damage. If the object touched is either metal armor or a metal shield being worn or carried, it takes a permanent and cumulative -1 penalty to the AC it offers. Armor reduced to an AC of 10 or a shield that drops to a +0 bonus to AC it is destroyed. If the object touched is a held metal weapon, it rusts as described in your Rust Aura feature.

The Corroding Weapon deals an additional 2D6 Acid damage to Constructs.

Simply destroying the tools of the modern age is insufficient for your plans. You have developed techniques to destroy technological progress at a fundamental level. Once per long rest you can use an action and target one creature you can see and force them to make an INT saving throw DC equal to your spell save DC. On a failed save the target takes 3D6 Psychic damage and loses proficiency with one of the following skills for one hour: Arcana, History, Medicine, Religion, or one Tool. If you have seen the target cast a spell you can use this feature to instead lose the ability to cast that spell provided its level is less than your INT modifier (Minimum 1).

If the target fails the save by more than seven, the spell or proficiency is lost forever and cannot be relearned. If the target succeeds the saving throw they take half as much damage and have no other detrimental effects.

You can cast a perfected form of the spell Disintegration after much study. You can cast the spell Disintegration once per long rest without expending a spell slot. If the spell is cast this way hits a metallic object that is not worn or carried the object takes twice as much damage. If the spell hits a Construct the Construct takes an additional 30 damage and if the Constructs CR is less than your INT modifier (Minimum 1) the Construct is immediately destroyed.