Blight Wraith

Ethereal Sight. The Blight Wraith can see 60 feet into the Ethereal Plane when it is on the Material Plane, and vice versa.

Life Drain Aura. Any creature that starts its turn within 10 feet of the Blight Wraith must succeed on a DC 11 Constitution saving throw or take 4 (1d8) necrotic damge and have their hit point maximum reduced by an amount equal to the necrotic damage taken. This reduction lasts until the creature finishes a long rest. If this effect reduces a creature's hit point maximum to 0, the creature dies, and its soul is consumed by the Blight Wraith, which regains hit points equal to the creature's hit point maximum.

Incorporeal Movement. The Blight Wraith can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Multiattack. The Blight Wraith makes two Withering Touch attacks.

Withering Touch. Melee Spell Attack: +4 to hit, reach 5 ft., one target. Hit: 8 (2d6 + 1) necrotic damage.. 

Dreadful Moan (1/Day). Each creature within 15 feet of the Blight Wraith that can hear it must succeed on a DC 11 Wisdom saving throw or be frightened for 1 minute. A frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Spectral Recoil. When a creature within 5 feet of the Blight Wraith hits it with a melee attack, the Blight Wraith can use its reaction to force the attacker to make a DC 11 Wisdom saving throw. On a failed save, the attacker takes 3 (1d6) necrotic damage and has disadvantage on their next attack roll before the end of their next turn.