Cloak of Doom

An aura of necrotic energy forms around the caster, which sucks life from the surrounding creatures. The aura has a range of 5-foot radius from the caster and is visible. Any creature that begins its turn in it, must succeed on a Constitution Saving Throw or take 1d6 necrotic damage + proficiency bonus. Additionally, at the start of the caster's turn, they gain a number of temporary hit points equal to the highest number of hit points that the aura has drained since the end of their last turn. Constructs automatically succeed on the saving throw.