Aura of Fear. the abyssal horror has an aura of pure terror around it. it is a 20 foot sphere, centered on the abyssal horror. when a creature enter's it for the first time or ends their turn in it, they must make a DC 16 wisdom saving throw. on a failed save, they are frightened of the abyssal horror for a round. 

Weapon's of Terror. when the abyssal horror deals damage to a creature, that creature must make a DC 16 wisdom saving throw. on a failed save, they are frightened of the abyssal horror for a round. 

Maddening Fear. the abyssal horror's fear is so powerful, it drives many insane. at the start of a creature frightened of the abyssal horror's turn, the creature must make a DC 16 wisdom saving throw. on a failed save, it takes 7 (2d6) psychic damage, and must use it full movement to move away from the abyssal horror. the creature will not move into any obvious hazards in this movement.

Multiattack. the abyssal horror makes three melee attacks.

Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., 1 target. Hit: 5 (1d4 + 3) slashing damage. if the target is frightened, it takes 10 (3d6) additional psychic damage. 

Abyssal Blast. Ranged Weapon Attack: +4 to hit, range 120/360 ft., 1 target. Hit: 10 (2d8 + 1) psychic damage. if the target is not frightened, they must make a DC 16 wisdom saving throw, becoming frightened for a round on a failed save. is they are frightened, then they take an additional 11 (2d10) psychic damage.