Avalon

This small globe portrays a small island wreathed in a morning's glow. The singular tree seemingly looming over what appears to be a lone grave. A sword stands as the headstone. While attuned to this item at the beginning of each of your turns when you are not at full health all creatures within 10 feet of you take 1d8 necrotic damage you heal for twice the amount of damage taken. This effect does not activate if you are unconscious at the beginning of your turn.  

Notes: This item can only be attuned to by