Sources
CR
Type
Size
Alignment
Movement

Nightveil Specter

Medium Undead, Neutral Evil

Armor Class 17 (natural armor)
Hit Points 105 (14d8 + 42)
Speed 30 ft.
STR
18
+4
DEX
19
+4
CON
16
+3
INT
6
-2
WIS
17
+3
CHA
11
+0
Saving Throws DEX +8, WIS +7
Skills Insight +7, Perception +7, Stealth +8
Damage Resistances necrotic; bludgeoning, piercing, slashing, from nonmagical attacks
Damage Immunities poison
Condition Immunities Charmed, Exhaustion, Frightened, Poisoned
Senses darkvision 120 ft., passive Perception 17
Languages understands Common but can't speak
Challenge 10 (5,900 XP)

Traits

Mount. If the specter isn't mounted, it can use a bonus action to magically teleport onto its gloamwing mount, provided the specter and the gloamwing are on the same plane of existence. When it teleports, the specter appears astride the gloamwing along with any equipment it is wearing or carrying. While mounted and not incapacitated, the specter can't be surprised, and both it and its mount gain advantage on Dexterity saving throws.

Actions

Multiattack. The specter makes two scythe attacks.

Scythe. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit:11 (2d6 + 4) slashing damage plus 13 (3d8) psychic damage.

Mind Twist (Recharge 5–6). The specter magically emits psychic energy in a 60-foot cone. Each creature in that area must succeed on a DC 15 Wisdom saving throw or take 22 (5d8) psychic damage and be stunned for 1 minute. The stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Reap Memory (3/Day). The specter touches one incapacitated creature and chooses 1 hour from among the past 24. Unless the creature succeeds on a DC 15 Intelligence saving throw, the creature loses all memory of that hour. The creature regains the memory only if the specter dies within the next 24 hours.

Lore

The Nightveil specters of Ravnica are hooded, undead guardians that ride flying creatures called gloamwings. They are fearsome agents of House Dimir, protecting the territory and interests of that guild-particularly the neighborhood of Nightveil, from which the specters get their name. Their work can include driving off people who accidentally wander too close to a secret rooftop meeting, killing those who knowingly infiltrate Dimir property, and tracking those who have stolen guild secrets,…