You specify a position for the device to fly to within range and which you can see, and it flies to that spot, deploying itself (immovable once deployed).   Upon deployment, a storm cloud appears in the shape of a cylinder which is 10 feet tall and has a 60 feet radius centered 100 feet above the deployed device.   Lightning begins to fall from the storm cloud directly at the point where the device deployed. If an enemy is within 5 feet of the point of a lightning strike, they must make a DEX saving throw, and on a failure, they take 3d10 lightning damage. Half as much on a successful save. On each of your turns until the end of the effect, you may use your action to call down further lightning strikes down from the storm cloud anywhere in the area covered by the storm cloud.   If you are outside and it is already in stormy conditions, then the device harnesses the power of the existing storm as opposed to forming a new one. Under these conditions, the damage is increased by an additional 1d10.