Eyes of the Dark. (1/Long Rest): As a bonus action, the Vnsvng can cast Darkness. When it casts, it can see normally through the magical darkness.

Fey Ancestry. Vnsvng has advantage on saving throws against being charmed, and magic can't put it to sleep.

Elven Accuracy. If Vnsvng has advantage on an attack roll, it can reroll one of the dice once.

Eldritch Smite. Once per turn when Vnsvng hits a creature with its longbow, it can expend a Pact Magic spell slot to deal an extra 3d8 force damage to the target and it can knock the target prone if it is Huge or smaller.

Spellcasting. The Vnsvng is a 8th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). The Vnsvng has following spells prepared:
Cantrips (at will): Eldritch Blast, Minor Illusion, Toll the Dead
1st level (4 slots): Shield, Charm Person
2nd level (2 slots): Invisibility, Misty Step, Darkness
Pact Magic (3rd level, 2 slots): Hex, Thunder Step, Counterspell, Gaseous Form

Multiattack. Vnsvung can attack twice with its longbow.

Longbow. Ranged Weapon Attack: +8 to hit, reach 150/600 ft., one target. Hit: 9 (1d8 + 5) piercing damage. 

Greatsword. Melee Weapon Attack: +7 to hit, range 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.