Witch Bolt - Empowered

A beam of crackling, blue energy lances out toward a creature within range, forming a sustained arc of lightning between you and the target. Make a ranged spell attack against that creature. On a hit, the target takes 1d12 lightning damage, and on each of your turns for the duration, you can use your action, or bonus action to deal 1d12 lightning damage to the target automatically, provided you are within 30 feet of the target. 

If the target drops to 0 hit points before this spell ends, you can use an action or bonus action on a subsequent turn of yours to target a new creature.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the initial damage increases by 1d12 for each slot level above 1st.