Spellcasting. Ularan Mortus is a 10th-level spellcaster. His spellcasting ability is Charisma (spell save DC 16, +4 to hit with spell attacks). He regains his expended spell slots when he finishes a short or long rest. It knows the following warlock spells:

Cantrips (at will): chill touch, eldritch blast, mage hand, spare the dying

1st–5th level (4 5th-level slots): arms of hadar, bane, darkness, mirror image, counterspell, phantom steed, greater invisibility, shadow of moil, antilife shell, far step

Eldritch Mind: Ularan has advantage on Constitution saving throws that he makes to maintain his concentration on a spell.

Whispers of the Grave: Ularan can cast speak with dead at will, without expending a spell slot.

Grave Touched. Ularan doesn't need to eat, drink, or breathe. In addition, once during each of his turns, when he hits a creature with an attack and roll damage against the creature, he can replace the damage type with necrotic damage.

Necrotic Husk. When Ularan is reduced to 0 hit points, he can use his reaction to drop to 1 hit point instead and cause his body to erupt with deathly energy. Each creature of his choice that is within 30 feet of him takes necrotic damage equal to 2d10+10. He then gain 1 level of exhaustion. Once he uses this reaction, he can’t do so again until he finishes 1d4 long rests.

Multiattack. Ularan Mortus makes two attacks with his greatsword or two attacks with eldritch blast.

Pact Greatsword. Melee Weapon Attack: +8 to hit, reach 5ft., one target. Hit: 11 (2d6+4) slashing damage.

Eldritch Blast. Ranged Spell Attack: +8 to hit, reach 120ft., one target. Hit: 9 (1d10+4) force damage.

Form of Dread. Ularan manifests an aspect of his patron’s dreadful power. As a bonus action, he transforms for 1 minute. He gains the following benefits while transformed:

• He gains temporary hit points equal to 1d10+10.
• Once during each of his turns, when he hits a creature with an attack, he can force it to make a Wisdom saving throw, and if the saving throw fails, the target is frightened of him until the end of his next turn.
• He is immune to the frightened condition.
• He is immune to necrotic damage.
• Roll one additional damage die when dealing necrotic damage.

He can transform 4 times, and regains all expended uses when he finishes a long rest.

The appearance of his Form of Dread represents Myrkul, as a shadowy shroud over a pale skull face, now augmented with the dead draconic wings of Ebondeath.