Culling Ritual

You invoke both death and life from a creature on the brink of both. When this spell is cast on a dying creature it must make a Constitution saving throw against your spell save DC. If it fails, the creature fails a death saving throw potentially killing the creature, as its life essence is extracted. You can keep stable a number of essence equal to your proficiency modifier. When you or another creature consumes this essence as an action, you heal for 2d8+your spellcasting modifier. A creature affected by this spell is immune to its effects for one year.

At Higher Levels. The healing increases by 2d8 for each spell slot level above 1.