Coil Shield

Armor (Shield)

Very Rare Requires Attunement

The Coil Shield has 8 charges and regains 1d4+1 charges every long rest. Additionally it also regains 1 charge when the wielder takes lightning damage.
Overcharge: As a bonus action, the wielder can expend 2 charges to double the shield's AC bonus until the end of their next turn.
Discharge: The wielder can expend one charge to cast the Magnetic Parry spell, replacing the material component and using the wielder's Str or Dex as the spellcasting ability.

Homebrew

Magnetic Parry

3-level Abjuration

Casting Time: 1 reaction, which you take when you are hit by a metallic object

Range/Area: Self

Components: Somatic, Material

Materials: A small piece of magnetite

Duration: Instantaneous

Project a magnetic barrier that deflects metallic objects.

When you are hit a metallic object (such as a sword, an arrow with a metal head or a metal ball thrown with the catapult spell), you may use your reaction to deflect the attack. The damage dealt by the attack is reduced by 1d10 + your spellcasting ability modifier.
If this spell reduces the incoming damage to 0, you may make a spell attack against the attacker, using the range and base damage of the weapon or spell that was used to make that attack.

Available for: Wizard, Sorcerer, Bard, Armorer

Faraday Shield: The wielder has resistance to lightning damage while using this shield.

A very lightweight shield consisting of a thin coil of copper wire about 1 ft. in diameter. The shield is powered by an arcane battery and projects a magnetic field that repels incoming attacks.