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

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

Flyby. The dragon doesn't provoke opportunity attacks when it flies out of an enemy's reach.

Avoidance. When the Valstrax is subjected to an effect that requires it to make a saving throw to take half damage, it instead take no damage on a success and half damage on a failure.

Multiattack. Valstrax makes one Bite attack and two Claw attacks.

Bite. Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 21 (2d10 + 10) piercing damage.

Claw. Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 17 (2d6 + 10) slashing damage.

Dragon Missiles. Valstrax launches three glowing missiles out of its wings at three unique targets within 90 feet. Each takes 19 (3d8 + 6) fire damage and must succeed on a DC 25 CON saving throw or be affected by Dragonblight for 1 minute. 

Trident Spear Wing. After the dragon has used it's Thrust legendary action, it can add one of two more moves to this attack:

• Spin: Spins while the wing is still outstretched, causing each creature within 15 feet of the dragon must succeed on a DC 25 Dexterity saving throw or take 17 (2d6 + 10) slashing damage, half as much on a successful save. Prone targets succeed automatically.
  
  
• Slam: Slams the tip of its wing into a location within 10 ft. All creatures within 5 ft. of the location must succeed on a DC 25 DEX saving throw or take 17 (2d6 + 10) bludgeoning damage, half as much on a success. Prone targets fail automatically.

The dragon can take 4 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.

Claw. Valstrax makes a claw attack.

Dragon Missiles (Once per round). Valstrax makes a Dragon Missile Attack.

Dragon Rush (Costs 2 actions). The Valstrax flies up to 100 ft. directly forward without provoking attacks of opportunity. If it passes through another creatures space, that creature must succeed on a DC 25 Dexterity saving throw or take 26 (3d10 + 10) bludgeoning damage and fall prone. On a success creatures take half damage and are not knocked prone.

Thrust Attack (Costs 3 Actions). The dragon rears back one of its wings before connecting it into a jagged spear-like formation and thrusting it in a line 15 feet long and 5 feet wide. Each creature hit must succeed on a DC 25 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning damage and be knocked prone. 

Valstrax possesses two mythic actions that can be each used after it has lost 200 hp. Each attack is used at the start of the round and Valstrax cannot do anything outside the attack, including movement and legendary actions. For each recharge, use a d10 instead of a d6.

Crimson Cannon (Recharge 9-10). Valstrax bends both wings forwards and channels, blasting out a massive beam of energy in a 120 ft. long, 15 ft. wide line. Each creature must make a DC 25 DEX saving throw, taking (8d6) fire damage and being inflicted with Dragonblight for 1 minute on a failure or half damage on a success. If a creature starts or ends their turn in the beam, they repeat the throw. While channeling, Valstrax is immune to all conditions and cannot be forcefully moved. 

At the end of the round, Valstrax ends his beam by ripping it across the ground, allowing him to retarget the beam and changing the damage to Force.

Around the World (Once per fight, not counting inital landing). Valstrax sucks in air before blasting off, instantly breaking the sound barrier and circling overhead. All characters who can hear must succeed on a DC 35 CON saving throw or become stunned for 1 round, making another saving throw on the beginning of their turn to end the effect. While circling, Valstrax is untargetable, immune to damage and all conditions.

At the end of the round, Valstrax rockets towards the ground towards one creature of it's choice. Every creature in a 60-foot line that is 15 feet wide must make a DC 25 Dexterity saving throw, taking 45 (10d8) Fire damage and 45 (10d8) Bludgeoning damage on a failed save, or half as much damage on a successful one. If used as an opening move, the damage is reduced to (8d6) Fire and (8d6) Bludgeoning.