Aspect of Demogorgon

Innate Spellcasting. The Aspect's spellcasting ability is Charisma (spell save DC 19). It can innately cast the following spells, requiring no material components:

At will: detect magic, invisibility, major image
3/day each: dispel magic, fear, darkness

Legendary Resistance (2/Day). If the Aspect of Demogorgon fails a saving throw, it can choose to succeed instead.

Magic Resistance. The Aspect of Demogorgon has advantage on saving throws against spells and other magical effects.

Two Heads. The Aspect has advantage on saving throws against being blinded, deafened, stunned, or knocked unconscious.

 Dominant Head. When the Aspect is summoned, one of its heads becomes dominant. The summoner determines which head is dominant, or the dominant head can be determined randomly. The Aspect gains the abilities associated with that head. The Aspect cannot change its dominant head. (Aameul or Hethrediah)

Aameul, the Cunning. An Aspect dominated by Aameul is manipulative, calculating, and cruel. It prefers to break its enemies' minds and turn them against one another rather than simply tearing them apart. The Aspect gains the following additional ability:

• Master of Manipulation. The Aspect has advantage on Charisma (Deception) and Charisma (Persuasion) checks

Hethrediah, the Savage. An Aspect dominated by Hethradiah is violent, impulsive, and destructive. It attacks with little concern for its own safety, seeking to overwhelm its enemies through terror and bloodshed. The Aspect gains the following additional ability:

• Savage Fury. Once per turn, when the Aspect hits a creature with a Tentacle attack, it deals an extra 7 (2d6) bludgeoning damage.

Multiattack. The Aspect of Demogorgon makes two tentacle attacks.

Tentacle. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 17 (3d10) bludgeoning damage. If the target is a creature, it must succeed on a DC 19 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 long rest. The target dies if this effect reduces its hit point maximum to 0.

Gaze. The Aspect turns the gaze of its dominant head toward one creature that it can see within 120 feet of him. That target must make a DC 19 Wisdom saving throw. Unless the target is incapacitated, it can avert its eyes to avoid the gaze and to automatically succeed on the save. If the target does so, it can't see the Aspect until the start of its next turn. If the target looks at it in the meantime, they must immediately make the save. The effect of the gaze depends on the Aspect's dominant head.

• Aameul's Gaze. If Aameul is dominant and the target fails its saving throw, the target is stunned until the start of the Aspect's next turn or until the Aspect is no longer within the target's line of sight.
• Hethrediah's Gaze. If Hethradiah is dominant and the target fails its saving throw, The target is confused until the start of the Aspect's next turn.

Legendary Action Uses: 2. Immediately after another creature's turn, the Aspect can expend a use to take one of the following actions. The Aspect regains all expended legendary actions at the start of its turn.

Tail. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 20 (2d10 + 7) bludgeoning damage plus 9 (2d8) necrotic damage.