Equivalence

Choose a willing creature within 60 feet and reduce it 0 hit points. Then, choose nother creature within 60 feet. At the end of the second target's next turn, it must succeed on a Constitution saving throw or take necrotic damage equal to the hit points the willing creature lost, including temporary hit points.

If you stop concentrating on this spell before the end of the target's next turn, the spell fails and the creature does not make a saving throw.

If you target the same willing creature twice within a 24-hour-period, the spell works but the willing creature dies.