Touch Of Death

 Make a attack against the creature to afflict it with the Pain of Decay. When hit by this attack the target takes 1d8 necrotic damage, and it can't regain hit points unless a healing spell is cast upon the afflicted Target.

If you hit a living target, it also has disadvantage on attack rolls against you until the end of your next turn.

This spell's damage increases by 1d8 when you reach 7th level (2d8), 14th level (3d8), and 18th level (4d8).