Red Sign

You reach above your head and conjure the dreaded Red Sign, a sigil of immense power that is inimical to all creatures. At the end of each of your turns for the duration, each creature (including yourself) within 30 feet of you that can see you takes 5d8 (avg 22.5) type=necrotic damage. This damage can't break your @status[Concentration|XPHB]. If this damage reduces a creature to 0 @variantrule[Hit Points|XPHB], it and everything nonmagical it is wearing and carrying collapses into a pile of slime and viscera. The target can be revived only by a @spell[True Resurrection|XPHB] or a @spell[Wish|XPHB] spell.