Crash Lightning

The next time you make a melee weapon attack during the spell’s duration, the weapon crackles with the power of storms.  Make the attack roll as normal. The target takes 6d10 lightning damage on a hit, or half as much damage on a miss, instead of the weapon’s normal damage.

Whether you hit or miss, each creature(except yourself) within 10 feet of the target must make a Constitution saving throw. Each of these creatures takes 1d8 Thunder damage on a failed save, or half as much damage on a successful one.

The weapon then returns to its normal form.