Acerbic Bolt

Form swirling clouds in the sky above you. For the duration, a beam of green lightning continually tethers to you from the clouds, preventing you from moving. As an action you can target a creature that you can see with a tendril of lightning within 60 feet of you dealing 3d6 lightning damage. Each creature within 10 feet of that point must make a Dexterity saving throw or take 4d4 acid damage.