Abyssal Pain

Calling upon deep-seated pain within yourself, you cut your current health in half. Then, you release a wave of necrotic energy in a 40 ft. circle around you. All enemies in that range must make a Dexterity saving throw against your spell save DC or take necrotic damage equal to 2 times the amount of health consumed. On a succeeded save, enemies take half damage.

Any enemy that failed its save has its blood infected with your pain and, at the start of your next turn, is damaged by the same amount again. This secondary damage heals you by the same amount.