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

lightning absorbtion

if the dragon is subjected to lightning damage, it takes no damage and instead regains an amount of hit points equal to the amount of damage taken

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws. if it can, it makes an attack with its missile pods.

Bite. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) piercing damage plus 14 (4d6) fire damage, and 15 poison damage.

Claw. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 17 (2d6 + 10) slashing damage, and 17 poison damage.

Tail. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage and 19 slashing damage. the target must suceed on a dc15 dexterity save or drop prone.

Frightful Presence. Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 21 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 for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Flamethrower (Recharge 5–6). The dragon exhales fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 91 (26d6) fire damage on a failed save, or half as much damage on a successful one.

Mouth Cannon (Recharge 2 turns). the dragon shots a cannon with 200 foot range 86 (23d6) fire damage on a failed save, or half as much damage on a successful one, and 3d6 bludgeoning damage.

missile pods (recharge 2 turns)

the dragon fires 10 missiles from a missile pod, with 200 foot range. the missiles automaticly hit and deal 2d6 fire damage and 3d6 bludgeoning damage.

Countermissiles(recharge 2 turns)

if the dragon is targeted by a range weapon attack, it automatcally misses, being destroyed by the countermissiles

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 its 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 15 feet of the dragon must succeed on a DC 25 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.