Circle of Shadows

when enchanted items blade becomes visible it engulfs the caster in a 20 ft radius of 2 feet high thick shadows that seem to pour out of the ground that gives the wielder advantage on intimidation checks. any creature that enters the field of darkness must make a DC 13 str check against being restrained. every time a creature finishes their turn while restrained in the thick shadows it takes 2d10 necrotic damage.