Originating from a creature from deepest depths of the abyss, this eye grants the user access to its overwhelming power. As an action you can activate the eye, the eye remains active for 1 hour. You suffer a 1d10 reduction to your maximum HP until eye is deactivated, lost health is not restored until you complete a short or long rest. The eye can be activated a number of times equal to your proficiency bonus. All uses are restored upon a long rest.

Upon activation the user gains blindsight out to 60ft. 

Once per long rest, while the eye is activated, you can release the power of the abyss within the eye. A target within 120ft must succeed a DC 15 constitution saving throw or suffer 4d10 necrotic damage, half as much on a successful save. The immense power harms the user as well. The user suffers half the damage dealt. 

Notes: six hours of meditation for the magic of the eye to merge with the forehead. Can be done over a long rest, however upon waking you will suffer 2d10 necrotic damage, Social, Utility, Combat