Multiattack

The wraith lord can use Paralyzing Terror. It then uses Life Drain twice. If in corporeal form it then makes a greatsword attack.

Life Drain

The wraith targets a creature within 5 feet forcing it to make a DC 18 Constitution saving throw. On a failure the creature takes 17 (5d6) necrotic damage or 24 (7d6) necrotic damage if it is frightened or surprised and its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the creature finishes a long rest. It dies if its hit point maximum is reduced to 0.

Greatsword (Corporeal Form Only)

Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage plus 17 (5d6) poison damage and the target makes a DC 18 Constitution saving throw. On a failure the target is poisoned for 24 hours. While poisoned in this way the target can't regain hit points. If a creature dies while poisoned in this way its spirit rises as a wraith under the wraith lords control 1 minute after its death.

Paralyzing Terror

The wraith lord targets a frightened creature within 60 feet forcing it to make a DC 18 Wisdom saving throw. On a failure the target is paralyzed for 1 minute. It repeats the saving throw at the end of each of its turns ending the effect on itself on a success.

Create Wraith

The wraith lord touches a humanoid corpse it killed up to 1 day ago. The creatures spirit rises as a wraith under the wraith lords control.

Corporeal Form (1/Day)

The wraith lord takes on a material form. In material form it loses its incorporeal trait its fly speed and its immunity to the grappled prone and restrained conditions. The wraith instantly reverts to its incorporeal form if it is bloodied and it can do so voluntarily at any time as an action.