Abyssal Form. The elemental can move through a space as narrow as 1 inch wide without squeezing.
Devour Light. A 15-foot radius of magical darkness extends out from the elemental, moves with it, and spreads around corners. Darkvision can't penetrate this darkness, and no natural light can illuminate it. If any of the darkness overlaps with an area of light created by a spell of 3rd level or lower, the spell creating the light is dispelled
Multiattack. The elemental makes two attacks.
Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage.
Mind Rake. Ranged Weapon Attack: +7 to hit, range 120/360 ft., one target. (2d10 + 4) psychic damage.
Horrific Stare (Recharge 4-6). Each creature within the darkness created by the elemental must succeed a DC 15 Wisdom saving throw or take 6 (1d10) psychic damage and be frightened of the elemental until the end of their next turn.
Spreading darkness. To protect the master, the elemental can, for a brief moment, harden the darkness, reducing the damage of an oncoming attack to half.
Description
The space between all things is darkness, and just like light, it emits energy. The negative energy of nothingness creates physical forms, just like any other elements, and as such, shadow elementals can form. Shadow elementals are not inherently evil in nature, though they can be very aggressive.
As the connection to the shadows deepens, it becomes impossible to shake the feeling of loss and death. Maybe this is the first step of the final rebirth, becoming who the stars have been seeking restlessly for so long.