Vitality Well

 A black orb appears in your hand, and begins to siphon the life force of a living creature you can see within range.

The target must make a Constitution saving throw.  The target takes 8d8 necrotic damage on a failed save, or half as much damage on a successful save.  On a failed save, the target also ages a number of years equal to half the damage dealt, and you may choose to decrease your age by 1d8 years.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d8 for each slot level above 6th.