Annihilation

A monochromatic beam of raw energy erupts from the creature's hand, concentrated into a line 120 feet long, and 5 feet wide. Each creature in the line must make a dexterity saving throw. On a failed save, a creature takes 27 (6d8) force damage. On a successful save, it takes half as much damage. Creatures with the ability to cast spells have disadvantage on this check.