Avariel's Sustained Shock

A lancing arc of electrical energy lashes out toward a creature within range, forming a sustained arc of lightning between caster and target. Make a ranged spell attack against that creature. On a hit, the target takes 2d4 lightning damage, and on each of your turns for the duration, you can use your action to deal 2d4 lightning damage to the target automatically. The spell ends if you use your action to do anything else. The spell also ends if the target is ever outside the spell’s range or if it has total cover from you.

This spell's damage increases by 2d4 when you reach 5th level (4d4), 11th level (6d4), and 17th level (8d4).