When you hit a target with this magical bolt, you can speak a command word to summon a bolt of lightning from the sky, centered on the target. If the creature cannot see the sky, this command word fails. Each creature within 5 feet of the target must make a DC 15 Dexterity saving throw, taking 6d6 lightning damage on a failed save and half as much on a successful one. The bolt then becomes non-magical.