Darkbeam

A beam of negative, dark energy flashes out from your hand in a 5-foot-wide, 60-foot-long line. Each creature in the line must make a Constitution saving throw. On a failed save, a creature takes 6d8 necrotic damage and can't benefit from any healing until your next turn. On a successful save, it takes half as much damage.

You can create a new line of darkness as your action on any turn until the spell ends.

For the duration, a mote of dark, evil energy shines in your hand. It sheds dim, purplish light in a 30-foot radius.