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

Magic Weapons. The dragon's attacks are magical.

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

Multiattack. The dragon can use one spell. It then makes two attacks: one with its bite and tail or two with its claws.

Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 31 (4d8 + 12) piercing damage.

Claw. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 25 (3d8 + 11) slashing damage.

Tail. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 27 (4d8 + 9) slashing damage.

Breath Weapons (Recharge 5–6). The dragon uses the following breath weapon.

Psychic Breath. The dragon exhales an distorting blast in a 60-foot cone. Each creature in that area must make a DC 20 Constitution saving throw, taking 67 (16d8) psychic damage on a failed save and roll from the Wild Magic Surge Table, or half as much damage on a successful one with no magic surge occuring.

Spellcasting. The dragon is a 12th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 18, +10 to hit with spell attacks). It requires no material components to cast its spells. The dragon has the following sorcerer spells prepared: 

Cantrips (at will): dancing lights, thunderclap, minor illusion, mind sliver, shape water, mold earth

1st level (4 slots): disguise self, shield, charm person, sleep

2nd level (3 slots): tasha's mind whip, shatter, mind spike

3rd level (3 slots): thunder step, tidal wave, wall of water

4th level (3 slots): blight, greater invisibility, polymorph

5th level (2 slots): synaptic static, dominate person

6th level (1 slot): globe of invulnerability