Breath of Dying Star

You summon a cloud of darkness that explodes around you in all directions. Creatures touched by the darkness take 1d8 necrotic damage and can't regain hit points as long as they are in 30 feet reach of you or until dispelled.

This spell's damage increases by 1d8 when you reach 5th level (2d8), 11th level (3d8), and 17th level (4d8).