Burning fireflies

You create a 5ft diameter sphere of burning hot sparks or fireflies in a point within range. Any creature that ends it’s turn in the sphere takes 1d4 fire damage. As a bonus action on each of your turns, you can move the fireflies up to 20ft and you can make them streak to a point that is 30ft away from the sphere. Any creature in the 5ft wide, 30ft long line must make a con save or take 2D4 fire damage and be blinded until the end of their next turn on a failed save or half as much and no blindness on a successful save. The fireflies shed bright light for 20ft and dim light for an additional 20ft.