The Tenth Circle's Bounty

Once per Long Rest, as an action, you may choose a creature you can see within 30ft to make a Constitution Saving Throw DC 15. On a failure, the creature will take necrotic damage equal to d10s x Proficiency Bonus, e.g. PB=2: 2d10, PB=3:3d10, etc. On a success, the creature takes half damage. In either case, you will then heal an amount of HP equal to the damage dealt.