Awakened Coin of the Storm Emperor

Once per short rest, when you take acid, cold, fire, lightning, or poison damage, you can use your reaction to reduce the damage taken by 2d10. This elemental power is stored in the coin. When you hit with a weapon attack after reducing damage in such a way, you can expel the stored power to deal 2d10 additional lightning damage with the attack, using the charge. If you don’t expel the power until you take a short or long rest, the charge is lost.