Dry and Rejuvinate

10-foot-radius sphere centered on a point within range.
Each creature of your choice in that area makes CON save,  2d6 necrotic damage on a failed save, or half as much damage on a successful save. Vegetation in the area drys up.

Additionally one creature of choice in the area can spend one of its unspent Hit Dice and regain a number of hit points equal to the roll plus the spellcasting ability modifier.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot above 2nd, and the number of Hit Dice that can be spent and added to the healing roll increases by one for each slot above 2nd.