Delayed Lightning Fulmination

You send magic through your fingertips and into an object or creature. Until you reactivate the ability, the creature's hair, if it has hair, stands on end and everyone within 5 feet will be able to hear a faint hum emanating from where you touched. When activated again as a bonus action, and as long as you are within 120 ft, a lightning bolt strikes down on the object/creature from 10 ft above them. The target has to make a dexterity saving throw. On a failed save they take 4d8 lightning damage and on a successful one they take half as much. Anything in between the start of the lightning and the target also has to make a dexterity saving throw. On a failed save they 2d4 lightning damage and on a successful one, half as much. If any creatures have metal armor on, they have disadvantage on the dexterity saving throw. Ignore constructs in between start of lightning bolt and target.