As a wave of necrotic energy flows out of you in an instant, a chill in the air drops the temperature to icy cold in a radius of 200 ft. centred on you. You focus this energy to a single point as a ray of black force shoots from the eyeballs centre. Targeting a single creature, you make a spell attack against it and on a hit, the target takes 10d10 points of necrotic damage. A creature hit by this spell has to make a constitution saving throw or gain one point of exhaustion as the life is drained from them. If the target is an Undead they take half damage and does not have to make the saving throw against gaining exhaustion, and if the target is a Construct it is unaffected.