Adult Lapis Lazuli Dragon

Legendary Resistance (3/Day, or 4/Day in Lair). If the dragon fails a saving throw, it can choose to succeed instead.

Multiattack. The dragon makes one Bite attack and two Claw attacks.

Bite. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 7 (2d6) psychic damage.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 10 (1d8 + 6) slashing damage.

Spellcasting (Psionics). The dragon casts one of the following spells, requiring no spell components and using Intelligence as the spellcasting ability (spell save DC 17):

At will: Mage Hand (the hand is invisible), Minor Illusion
1/day each: Detect Thoughts, Dispel Magic, Invisibility, Major Image

Disorienting Breath (Recharge 5–6). The dragon exhales a wave of psychic dissonance in a 60-foot cone. Each creature in that area must make a DC 18 Intelligence saving throw. On a failed save, the creature takes 42 (12d6) psychic damage, and until the end of its next turn, when the creature makes an attack roll or an ability check, it must roll a d6 and reduce the total by the number rolled. On a successful save, the creature takes half as much damage with no additional effects.

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature’s turn, the dragon can expend a use to take one of the following actions. The dragon regains all expended uses at the start of each of its turns.

Blazing Light. The dragon uses Spellcasting to cast Psychic Scream.

Pounce. The dragon moves up to half its Speed, and it makes one Rend attack.

Mind Crush. Constitution Saving Throw: DC 18, one creature the dragon can see within 120 feet. Failure: 27 (6d8) Psychic damage, and the target’s Speed is zero until the end of its next turn. Failure or Success: The dragon can’t take this action again until the start of its next turn.