Blood Rain

Warm, blood-like liquid begins to rain down in a 15ft radius, 60ft high cylinder at a point within range. When a creature enters the area for the first time or starts it's turn there, it must make a Constitution saving throw. On a failed save, the creature takes 2d8 necrotic damage. On a successful save, the creature takes half as much damage. You may use an action on each of your turns to move the cylinder up to 20ft. to a point within range.

This spell has the inverse effect on undead. Undead in the spell's area instead heal for 1d8 when they enter the area for the first time or when they start their turn there.