Chaotic High Priest of Death

Inescapable Destruction. Necrotic damage dealt by the Death Priest ignores resistance. 

Spellcasting. The priest is a 9th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 15, +7 to hit with spell attacks). It has the following cleric spells prepared:

Cantrips (at will): toll the dead, mending, resistance, word of radiance
1st level (4 slots): false life, inflict wounds, healing word, ray of sickness
2nd level (3 slots): blindness/deafness, hold person, ray of enfeeblement, silence, spiritual weapon
3rd level (3 slots): animate dead, bestow curse, dispel magic, protection from energy, spirit guardians, vampiric touch

Unholy Staff. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage plus 4 (1d8) necrotic damage. 

Unholy Casting. As an action, the unholy priest absorb the power of the unholy nature around him restoring a 1d4 spell slot. The result being the level of the spell being recovered. 

Chaotic Dispel. The Death Priest rolls a d20, on a 15-20, the spell is dispelled, on a one however, the spell is a critical against the priest.

The Death Priest can take 1 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The Death Priest regains spent legendary actions at the start of its turns.

Reaper. The Death Priest can cast Toll the Dead on one creature within range that are within 15 feet of the dark priest. 

Upon Death, The Dark Priest raises himself, gaining any abilities of a Wraith Lord. He heals to maximum HP of 120 (15d8+45). AC is now 20 and is immune to necrotic, poison, charmed, exhaustion, and cold. He is now susceptible to psychic damage.  

Actions

Multiattack. The Dark Priest Wraith can make 1 Physical Attack, and Cast 1 Spell attack. 

Reaping Unholy Staff. Melee Weapon Attack: +8 to hit, reach 5 ft., one creature. Hit: 10 (2d8 + 3) necrotic damage. The target must succeed on a DC 14 Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a short rest. The target can not die by having their max HP reduced. This attack critically hits on a roll of 19-20 and on a critical hit, the wraith absorbs half of the damage dealt.

Create Specter. The wraith targets a humanoid within 10 feet of it that has been dead for no longer than 1 minute and died violently. The target's spirit rises as a specter in the space of its corpse or in the nearest unoccupied space. The specter is under the wraith's control. The wraith can have no more than seven specters under its control at one time.

Touch of Chaos (recharge 5-6). The Death Cleric makes a Unholy attack. If the attack hits, the enemy must roll a d20. On a d10 or lower, they are hit with an additional 23 necrotic damage. 

Spells

4th level (3 slots): blight, death ward, freedom of movement, guardian of faith
5th level (1 slot): contagion, insect plague

Legendary Actions

Aura of Dread. An aura of fear surrounds the wraith king. Each creature within 25 feet of the wraith king must succeed on a DC 15 Wisdom saving throw or be frightened until the end of the creature's next turn. 

Channel Unliving Energies. (Recharge 1-2) The wraith king magically unleashes negative energy. Creatures within 60 feet of the wraith king, including ones behind barriers and around corners, can't regain hit points until the end of the wraith king's next turn.