Target a location and at the start of each round a blast of magical energy strikes it. While this spell is active, at the start of your turn any creature within 10 feet of the location or if any creature that moves to a space within 10 feet of the location for the first time on a turn must succeed on a Dexterity saving throw. The creature takes 2d10 Piercing damage on a failed save, or half as much damage on a successful one.