You call up a black veil of necrotic energy that devours the living. You draw on the life energy of all living creatures within 30 feet of you that you can see. When you cast the spell, every living creature within 30 feet of you that you can see takes 1 necrotic damage, and all those hit points transfer to you as temporary hit points.    The damage and the temporary hit points increase to 2 per creature at the start of your second turn concentrating on the spell, 3 per creature at the start of your third turn, and so on. All living creatures you can see within 30 feet of you at the start of each of your turns are affected. A creature can avoid the effect by moving more than 30 feet away from you or by getting out of your line of sight, but it becomes susceptible again if the necessary conditions are met. The temporary hit points last until the spell ends.