Aphotic Shroud

You pull the deepest reaches of the shadowfell to coat yourself in ragged, wisping shadow. You gain 3d12 + 12 temporary hit points, and while you have these temporary hit points you are considered to be heavily obscured to other creatures. If a creature hits you with a melee attack while you have these temporary hit points, they must succeed on a Wisdom saving throw or become Frightened of you until the end of their next turn.