Vigil of darkness

Choose  a creature of your choice that you can see within range. You cause a red seal to glow above his head. the creature must make a wisdom saving throw. if it fails, it takes 1d6 necrotic damage, on a save it takes only half. Until the spell ends, you can use a bonus action on each of your subsequent turns to cause this damage again.

At Higher Levels. When you cast this spell using a spell slot of 2rd level or higher, the damage increases by 1d6 for each slot level above 1nd.