Word of Despair

You chant an ancient command laced with dreadful magic to a creature within range. That creature must succeed on a wisdom saving throw or take 12d8 necrotic damage or half as much as a successful one. In addition, if they fail the initial saving throw, each day after the spell is cast on them they repeat the saving throw, ending the effect on a success, and taking another 12d8 necrotic damage on a fail. None of this spell's damage can be resisted or negated in any way.