Nightveil Specter

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.

The specter makes two scythe attacks.

Melee Weapon Attack +8 to hit, reach 10 ft., one target. 11 (2d6 + 4) Slashing damage plus 13 (3d8) Psychic damage.

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.

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.