Gargantuan dragon, neutral

Armor Class: 23

Hit Points: 580

Speed: 60 ft , fly: 120 ft , burrow: 60 ft , swim: 60 ft

STR

30 +10

DEX

16 +3

CON

30 +10

INT

26 +8

WIS

28 +9

CHA

23 +6

Saving Throws: CON +19, INT +17, WIS +18, CHA +16

Skills: Perception +27, Intimidation +21

Damage Immunities: Psychic, Necrotic, Force, Radiant, Thunder

Condition Immunities: Charmed, Frightened, Poisoned, Prone

Senses: Truesight 120 ft., Passive Perception 37

Languages: Common, Draconic, Celestial

Challenge Rating: 30

Actions

Multiattack. The aspect makes one Bite attack, one Claw attack, and one Tail attack.   Bite. Melee Weapon Attack: +19 to hit, reach 20 ft., one target. Hit: 23 (2d12 + 10) piercing damage plus 22 (4d10) necrotic damage.   Claw. Melee Weapon Attack: +19 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) slashing damage. If the target is a Huge or smaller creature, it is grappled (escape DC 20) and is restrained until this grapple ends. The aspect can have only one creature grappled this way at a time.   Tail. Melee Weapon Attack: +19 to hit, reach 15 ft., one target. Hit: 23 (2d12 + 10) bludgeoning damage. If the target is a creature, it must succeed on a DC 27 Strength saving throw or be knocked prone.     Reaving Breath (Recharge 5-6). The aspect inhales and draws in life in a 300-foot cone. Each creature in the area must make a DC 27 Constitution saving throw. On a failed save, the creature takes 71 (11d12) necrotic damage. On a successful save, the creature takes half as much damage. A creature reduced to 0 hit points from this attack dies and is unable to be restored to life without the use of a Wish Spell. Additionally, the aspect recovers half of the damage it inflicts with this attack.

Legendary Actions

The aspect 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 a nother creature's turn. The aspect regains spent legendary actions at the start of its turn.   Attack. The aspect makes one Claw or Tail attack.   Furious Bite (Costs 2 Actions). The aspect makes one Bite attack. If the attack hits a creature, the target must succeed on a DC 27 Wisdom saving throw or become frightened of the aspect until the end of its next turn.     Mythic Actions   If the aspect's Undying Wrath trait has been activate in the last hour, it can use the options below as legendary actions.   Death Shield (Costs 2 Actions). The aspect manifests an Avatar of Death for each hostile creature it is engaged with. These Avatars make a Reaping Scythe attack against each hostile creature and disappear immediately after. The aspect gains temporary hit points equal to the damage dealt until the start of its next turn.   Necrotic Flare (Costs 3 Actions). The aspect flares with necrotic energy. Each creature of the aspect's choice in a 60-foot-radius sphere centered on it must make a DC 27 Constitution saving throw. On a failed save, the creature takes 39 (6d12) Necrotic damage. On a successful save, the creature takes half as much damage.