Uth'oric, Demonic Deceiver

Magical Aura. Uth'oric has a 60 foot [Tooltip Not Found] affecting him at all times. Creatures outside that aura cannot see him. Uth'oric gains two Echo's on a long rest, which remain inside this aura. In addition, creatures making Death Saving Throws in this aura have it made by the DM instead. It also benefits from Comprehend Languages in this aura.

Hide Weakness: You're unable to discern this creatures weaknesses, immunities, or Vulnerabilities without a Successful DC 16 Insight Check with the Staff of Informing. It takes +2 Radiant Damage from sources.

Ego Boost: At the start of Uth'oric's turn, they gain a number of Temporary Hit Points equal to the number of Charmed creatures in its aura. If transformed, it becomes Frightened Creatures inside its aura.

Spellcasting. Uth'oric is a 4th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 16, +8 to hit with spell attacks). Uth'oric casts each spell at 3rd level, but can only cast each leveled spell once per long rest.

Mythical Illusion: When Uth'oric is reduced to 0 hit points, they gain 80 Hit Points, and their Illusion drops, revealing a Draconic Monstrosity with tentacles forming its wings. They gain additional Legendary Actions under Mythical Actions. They also gain 90 feet of flying, and Proficiency in all other Saving Throws.

Spellcasting: This creature can cast the following spells as an action once per long rest: 
Special: Bane (No concentration required), Alter Self (At will), Phantasmal Force (At will), 
Regular: Cause Fear, Command, Dissonant Whispers, Sleep, Silent Image, Blur, Crown of Madness, Detect Thoughts, Invisibility, see invisibility, Major Image

Alter Self Claws. +6 to hit, 5ft, 1d6 + 3 Psychic Damage. That creature makes a DC 16 Wisdom Saving Throw. On a failure, they're charmed (Untransformed) or Frightened (Transformed) for 1 minute. They can repeat this save at the end of each of their turns, and with a +2 bonus while outside Uth'oric's aura.

Cantrip Master: Uth'oric can cast the following cantrips as a bonus action without Verbal or somatic components, and without concentration. They can't cast the same cantrip twice in the same turn:
mind Sliver. - .mage hand. - .Thaumaturgy. - .Prestidigitation. - .Druidcraft. - .Minor Illusion

Spellcasting: This creature can cast the following spells as a bonus action once per long rest: 
Misty Step

Spellcasting: This creature can cast the following spells as a reaction once per long rest: 
Counterspell}

Legendary Resistance (Once): Uth'oric automatically succeeds against a spell. He gains an additional use when he transforms. 

Legendary Actions: Uth'oric has 3 Legendary Action points, which recharge on his turn. Each Legendary Action can only be used once per turn. When he becomes Mythical, he gains an additional Legendary Action.

Cantrip Master (Costs 1 action): Uth'oric casts a cantrip without Verbal or Somatic components.

Ego Boost (Costs 1 action): Uth'oric gains the Temporary Hit Points from his Ego Boost.

Spell Master (Costs 2 Actions): Uth'oric casts any leveled spell.

Distracting Echo (Costs 2 Actions). Uth'oric creates a copy of his untransformed self, placing it at a point inside his Trickster's Aura. Then, he can teleport to one of the echo's within 60 feet. The Echo's have 10 hit points, and an AC of 10. When Uth'oric casts a spell, the echo's copy how it looks like he's casting it. In addition, for every 5 feet he moves, the echo's move with him the same direction. player can use their action to make a Perception check against Uth'oric's spell save DC. On a success, the echo they looked at is known to be an illusion. Otherwise, they cannot discern if it's real.

Alter Self Claws: (1 Legendary Action Point): Uth'oric can make a Alter Self Claw attack. It becomes "Eldritch Claws"

Rending Tentacles: (2 Legendary Action Points, or an Action): +5 to hit, 1d4 + 2 Bludgeoning damage and 1d8 Psychic Damage. Can attempt to grapple as a Bonus Action, or for free if used as a Legendary Action.

Eldritch Breath (3 Legendary Action Points, or an Action. Recharge 6): Each creature in a 30-foot cone makes a Constitution Saving Throw (DC 14). On a failure, they take 2d10 Necrotic Damage, or half on a success. Creatures who failed make a Wisdom Saving Throw (DC 16) or are frightened.