Time Thief

You touch a creature and use the onyx as a conduit to age the target's physical form. The target must make a Constitution saving throw, taking 6d12 necrotic damage on a failed save, or half as much damage on a successful one. If the save fails, the target also ages by 1d4 years, adding half as much to your own life span. This spell has no effect on undead or constructs. You can also cast this spell as a ritual burning 100 gp worth of incense.

At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d12 for each slot level above 3rd.