Thunderstruck

Call down a burst of thunder onto a target you can see within 60ft. Make a ranged attack against the target. On a hit you do 1d8 Lightning damage (scaling to 2d8 at 5th level, 3d8 at 11th level, 4d8 at 17th level) to the target and they suffer a -2 penalty to the next Dexterity saving throw they make (scaling to -3 at 5th level, -4 at 11th level, -5 at 17th).