Shadowlisk

AC 20 (natural armor)
HP 92 (8d10 + 48; bloodied 46)
Speed 40 ft.
Initiative Dex +5 (15), Insight +1 (11), Perception +5 + 1d8 (15 + 1d8)

Proficiency +4; Maneuver DC 17
Saving Throws Str +5, Dex +9, Con +10, Int +2, Wis +5, Cha –2
Skills Athletics +9, Perception +5 (+1d8), Stealth +9 (+1d8)
Damage Resistances bludgeoning, piercing, and slashing while at least part of the shadowlisk is in dim light or darkness; necrotic
Senses truesight 120 ft., passive Perception 19
Languages understands Primordial and Sylvan but can’t speak

Abnegation (1/Encounter). If the shadowlisk fails a saving throw , it can succeed instead. Alternatively, it can use this trait to safely pass through conjurations and evocations until the end of its next turn.
Crepusculous and Adumbral. The shadowlisk has advantage on saving throws against spells and other magical effects. Its weapon attacks are magical. Magical darkness doesn’t impede its darkvision. While the shadowlisk is bloodied, magical darkness (as the spell darkness) seeps from its body in a 15-foot radius that moves with it.
Amorphous. A dark form slithers toward you, like a snake massive enough to swallow a man whole. The moment it touches light, its body explodes into vivid color, its clawed legs reach forward, and its massive eyes begin to glow. It’s difficult to look away. The shadowlisk can move through a space as narrow as 1 inch wide without squeezing.
Mirage Bane. Any creature that ends its turn in the shadowlisk’s line of sight and within 120 feet has its true form revealed, ignoring any illusions or transmutations. Magical effects are not dispelled or suppressed, simply seen through.

ACTIONS

Multiattack. It swipes at you, dances sideways in a dexterous coil of motion, then snaps its beak into your thigh. The shadowlisk chooses one of the following:
* It makes two attacks—Claw and then Beak—and can use Gloaming Leap before, between, or after the attacks.
* It makes a Claw attack, then uses Umbrafying Gaze.
Claw. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 36 (9d6 + 5) slashing damage.
Beak. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 38 (6d10 + 5) piercing damage. The shadowlisk then Shoves the target, trying to knock it prone.
Gloaming Leap. It sinks into its own shadow and vanishes. But you are too close, and your shadow is entangled with its, pulling you along. The shadowlisk magically teleports up to 30 feet to an unoccupied space it can see. The shadowlisk cannot use this action if its current location or destination are entirely brightly illuminated. When the shadowlisk teleports, any creature that is prone and within 5 feet of it also teleports, arriving in an unoccupied space next to the monster.
Umbrafying Gaze. Its eyes flash with the light of twin suns, obliterating your body and burning your mind and soul into the very ground you once stood upon. The shadowlisk magically focuses the light from its eyes in a path that is 25 feet long and 5 feet wide. Creatures in the path must succeed on a DC 18 Charisma saving throw, taking 38 (5d12 + 6) radiant damage on a failed save, or half as much on a successful one. A creature reduced to 0 HP by this damage is annihilated as its body burns away and its mind and soul are imprinted on the closest surface as a shadowy silhouette, suitable for consumption by shadowlisks. While it is annihilated in this way, a creature can perceive its immediate surroundings, but is incapacitated and stunned and cannot communicate.
If a different creature coats its hands with the blood of a shadowlisk, it can touch the mind and soul of a creature that has been annihilated within the last day and restore its body as an action. A creature restored in this way is alive and stable, with 0 HP.

REACTIONS

Obtenebrating Escape (1/Encounter). If the shadowlisk would take damage, it can use Gloaming Leap. If it does, the shadowlisk does not suffer the triggering damage or any effects attached to it. The area within 5 feet of the space it teleports to is covered in magical darkness until the end of the shadowlisk’s next turn.