Banger's Spark Fingers

Sparks of lighting fly from your fingertips and fall upon one creature of your choice within 60 feet that you can see, forming a normally harmless electric tether that connects your fingers to their body.  This tether is visible, but incorporeal, and stays tethered to a creature for as long as that creature is in range of this spell, or it ends.

When a creature tethered by this spell begins their turn, you may use your reaction to force all creatures tethered by your Banger's Spark Fingers to make a Constitution Saving throw.  Each creature that fails takes 3d6 lightning damage.  In addition, if the creature who triggered this reaction fails their save, their movement speed drops to 0 until the end of their turn.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you can target one additional creature for each slot level above 2nd.