Whispering Aura. At the start of each of the warlock's turns, each creature of its choice within 10 feet of it must succeed on a DC 15 Wisdom saving throw or take 10 (3d6) psychic damage, provided that the warlock isn't incapacitated.
Multiattack. The warlock makes two Dagger attacks.
Dagger. Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 5 (1d4 + 3) piercing damage plus 10 (3d6) psychic damage.
Howling Void. The warlock opens a momentary extraplanar rift within 60 feet of it. The rift is a scream-filled, 20-foot cube. Each creature in that area must make a DC 15 Wisdom saving throw. On a failed save, a creature takes 9 (2d8) psychic damage and is frightened of the warlock until the start of the warlock's next turn. On a successful save, a creature takes half as much damage and isn't frightened.
Spellcasting. The warlock casts one of the following spells, using Charisma as the spellcasting ability (spell save DC 15):
At will: detect magic, guidance, levitate, mage armor (self only), mage hand, minor illusion, prestidigitation