Tide of Death

You conjure up a wave of necrotic energy that crashes down on an area within range.  Each creature in that area must make a Dexterity saving throw. On a failed save, a creature takes 9d8 necrotic damage and is knocked prone. On a successful save, a creature takes half as much damage and isn’t knocked down. Undead and constructs are immune to this spell.

The water then spreads out across the ground in all directions, and then it vanishes.