Adult gloom dragon

Aura of gloom. A grey mist constantly roils around the gloom dragon and each creature that enters for the first time on their turn or ends their turn within 15ft of the gloom dragon must make a DC 18 Wisdom saving throw or be frightened. A creature can remake the save at the end of their turn. 

Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.

Magic Resistance. The gloom dragon has advantage on saving throws against spells and other magical effects.

Eternal consumption. The gloom dragon can eat a body resonantly killed by them if its no more than 2 size categories smaller than itself as an action. In 1 minute a tomestone shall appear on the gloom dragon's back. The tombstone plate records the consumed creature's name (if any), date and place of birth, and date and place of death. This can only be fixed via very very specific wish spell wording. After using wish the wish the creature then ca be resurrected but only if the gloom dragon is dead. 

Innate Spellcasting. The adult gloom dragon's innate spellcasting ability is Charisma (Dc 18). The adult gloom dragon can innately cast the following spells, requiring no material components:

3/day: sleep (4th level)

1/day: hold monster

Multiattack. The adult gloom dragon makes three attacks: one with its wasting bite and two with its claws.

Wasting bite. Melee Weapon Attack: +12 to hit, reach 10 ft., 1 target. Hit: 18 (2d10 + 7) piercing damage and the target must make a DC 18 Constitution saving throw or be inflicted with the grey wasting disease in which the creature has their charisma drained by 1d4 at the start of each hour.  

Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., 1 target. Hit: 14 (2d6 + 7) slashing damage. 

Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., 1 target. Hit: 16 (2d8 + 7) bludgeoning damage. 

Apathy breath (Recharges 5/6). The gloom dragon exhales apathy gas in a 60ft cone. Each creature within the radius must make a DC 18 Wisdom saving throw or be unable to take any actions other than movement. A creature can remake the save at the end of their turn. 

The adult gloom dragon can take 3 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 adult gloom dragon regains spent legendary actions at the start of its turn.

Detect. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Tombstone terror (Costs 2 Actions). The gloom dragon chooses one creature within 120ft of themselves that they can see and that creature must make a DC 18 Wisdom saving throw or take 31 (7d8) necrotic damage and can't take any actions until the end of your next turn.