Armor Class 17 (natural armor)
Hit Points 142 (15d8+75)
Speed 30 ft.
Saving Throws Con +10, Wis +9, Cha +8
Skills Arcana +17, Deception +13, Medicine +9, Perception +9, Stealth +9
Damage Immunities psychic, poison
Condition Immunities frightened, charmed, poisoned
Senses truesight 120 ft., passive Perception 19
Languages all, telepathy 60 ft.
Challenge 15 (13,000 XP)
Disquieting Technology. The whisperer is a highly advanced being that often carries pieces of powerful wands of fireballs shaped like staves with peculiar triggers, eyes of the eagle shaped as a pair of cylinders, or a helm of telepathy in the form of a glowing metal disc adhered to the side of the creature's head.
Magic Resistance. The whisperer has advantage on saving throws against spells and other magical effects.
Innate Spellcasting. The whisperer's innate spellcasting ability is Intelligence (spell save DC 20). The whisperer can innately cast the following spells, requiring no material components:
At will: alter self, detect magic, detect thoughts, disguise self, fear, identify, invisibility (self only), misty step, sleep, suggestion
3/day each: confusion, dimension door, disintegrate, dream, modify memory, plane shift, teleport
1/day each: feeblemind, meteor swarm, mind blank, weird
Multiattack. The whisperer in the darkness makes two Grasp of the Void attacks.
Grasp of the Void. Melee Spell Attack: +12 to hit, reach 5 ft., one target. Hit: 21 (6d6) force damage, and the target must succeed on a DC 18 Constitution saving throw or be stunned for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.