Very Rare Weapon (Shortsword), Finesse, Light, Requires Attunement

• This magical weapon deals lightning damage instead of piercing damage. 
• Deals extra 1d6 lightning damage or, increased to 2d6 if the target is wearing metal armor or is made of metal.

Cyclone Slash (Recharge 5-6). When you use the Attack action, you can replace one of your Attacks with this ability. You slash with the Tempest Blade and create a storm-like wave of energy in a 15-foot cone. All creatures caught in the area must make a DC 16 Dexterity saving throw, taking 2d6 lightning damage and being pushed 10 feet away from you on a failure, or taking only half damage and not being pushed on a success. 

Flash Storm. Once per long rest, you can use your action to conjure a swift lightning storm around you with a 30-foot radius. All creatures of your choice in the area must make a DC 16 Dexterity saving throw, taking 2d6 lightning damage on a failure, or half as much on a success.
All creatures with 0 hit points in the area become stabilized.