You surround yourself with an aura of necrotic energy that drains the life from those within 15 feet of you. When you cast this spell, you can designate any number of creatures you can see to be unaffected by it. When an affected creature enters the area for the first time on a turn or starts its turn there, it must make a Constitution saving throw. On a failed save, the creature takes 5d8 necrotic damage, and you gain the same number of hit points.

At Higher Levels. When you cast this spell using a spell slot of 9th level the damage increases by 2d8.