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

Multiattack. The dragon can use it's Frightful Presence. It then makes three attacks.

Bite. Melee Weapon Attack: +13 to hit, reach 5ft., one target. Hit: 16 (2d10+5) piercing damage. 

Claw. Melee Weapon Attack: +13 to hit, range 5ft., one target. Hit: 11 (2d6+5) slashing damage.

Tail. Melee Weapon Attack: +13 to hit, range 15ft., one target. Hit: 14 (2d8+5) bludgeoning damage.

Frightful Presence. Each creature of the dragon's choice that is within 120ft of the dragon and is aware of it must succeed a DC 18 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends on it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Aether Breath (Recharge 5-6). The dragon exhales a 60ft cone of raw blue tinged Aether. Each creature in that area must succeed a DC 19 Dexterity saving throw, taking 8d8 fire damage and 8d8 acid damage on a failed save, or half as much on a success.

The dragon 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 another creature's turn. The dragon regains spent legendary actions at the start of it's turn.

Detect. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 10 feet of it must succeed on a DC 19 Dexterity saving throw or take 11 (2d6+5) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.