Innate Spellcasting. The wraith's innate spellcasting
ability is Charisma (spell save DC 17). The wraith can
innately cast the following spells, requiring no material
components:
At will: darkness, dream, phantasmal force
3/day each: Evard's black tentacles, phantasmal killer
1/day: weird
Etherealness. The wraith enters the Ethereal Plane from
the Material Plane, or vice versa with a bonus action.
The wraith is invisible while on the Border Ethereal and
it can't affect or be affected by anything on the other
plane.
Multiattack. The wraith makes three attacks, one with its
sapping tether and two with its shadow claws.
Shadow Claws. Melee Weapon Attack: +11 to hit, reach
10 ft., one target. Hit: 24 (4d8 + 6) necrotic damage.
The target must succeed on a DC 17 Constitution
saving throw or its hit point maximum is reduced by an
amount equal to the damage taken. This reduction last
until the target finishes a long rest. The target dies if
this effect reduces its hit point maximum to 0.
Sapping Tether. Melee Weapon Attack: +11 to hit, reach
10 ft., one creature. Hit: 17 (2d10 + 6) psychic damage
and the target's Wisdom score is reduced by 1d6. The
target gains a hym's indefinite madness if this reduces
its Wisdom to 0. Otherwise, the reduction lasts until
the target finishes a short or long rest.