Bloodstar Destroyer Valstrax

Crimson Afterburn. While the valstrax is flying, a creature within 15 ft. of its flight path must make a DC 26 Dexterity saving throw. On a failed save, it takes 14 (3d8) fire damage or half as much damage on a success. If the valstrax takes the dash action, this damage is doubled.

Dive Attack. If the valstrax is flying and dives at least 120 feet straight toward a target and then hits it with a melee weapon attack, the attack deals an extra 36 (8d8) necrotic damage to the target and all other creatures within 30 ft. of the target (excluding the valstrax). The damage increases by 1d8 for every additional 10 ft. the valstrax flew beyond 120 ft. before it hit with its melee weapon attack. If the valstrax takes the dash action beforehand, the total necrotic damage dealt is doubled.

Dragonblight. When the valstrax deals necrotic damage to a creature, it must succeed on a DC 25 Constitution saving throw or be afflicted with dragonblight. While afflicted with dragonblight, the target can't deal cold, fire, lightning, necrotic, or thunder damage with its spells and attacks, and it can't impose any of the following conditions on other creatures: blinded, charmed, paralyzed, poisoned, and petrified. An afflicted creature can repeat the saving throw at the end of each of its turns, ending the effect on a success. Dragonblight can be cured early with the greater restoration spell or similar magic.

Dragonheart. While the valstrax's current hit points are below half of its hit point maximum, it gains resistance to cold, fire, lightning, and psychic damage, and it can score a critical hit on a roll of 17 to 20 on the d20.

Impact Event. Whenever the valstrax hits a creature that is no more than one size larger than it with a melee attack that is affected by its Dive Attack trait, the target and all other creatures that took necrotic damage from the valstrax's Dive Attack trait are knocked up to 60 (1d12 x 10 ft.) ft. away from the valstrax and also knocked prone. A creature smashed into a solid object takes 3 (1d6) bludgeoning damage for every 10 feet it was thrown. If a thrown creature crashes into another creature, that creature must succeed on a DC 26 Dexterity saving throw or take the same amount of bludgeoning damage as the thrown creature and be knocked prone. If the valstrax scores a critical hit on the attack, the target and any creature it crashes into are also stunned until the start of the valstrax's next turn.

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

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

Meteoric Torrent. Attacking prone creatures doesn't impose disadvantage on the valstrax's ranged attack rolls.

Resentment. Until the end of its turn, the valstrax gains a +4 bonus to attack and damage rolls against any creature that has damaged it since the end of its last turn.

Star of Despair (Mythic, recharges after a long rest). If the valstrax falls to 0 hit points, it doesn't die or fall unconscious. Instead, the valstrax regains all of its hit points, gains 200 temporary hit points, and it regains any expended uses of Legendary Resistance. The valstrax then starts to emit a barrier of dragon energy and debris, causing the area within 30 ft. of it to become lightly obscured and is difficult terrain for all creatures it chooses. If the valstrax takes radiant damage, additional debris is flung from its body, causing the area to be stained with its essence for 5 minutes. A stained area functions as difficult terrain for all creatures except for the valstrax. Until the valstrax uses its Crimson Star Beam, a creature affected by this difficult terrain must spend 3 feet of movement for every 1 foot it moves in the area. Additionally, the valstrax can now use the options in the "Mythic Actions" section for 1 hour, it immediately saves against all ongoing conditions and effects, and gains 1 extra turn in the initiative order (roll initiative again to determine when its second turn occurs). The experience for fighting a Bloodstar Destroyer Valstrax after it activates this trait is 3x its standard XP value (465,000 XP).

The Red Comet. The valstrax doesn't provoke opportunity attacks when flies out of an enemies reach, difficult terrain doesn't cost it extra movement, and magic can neither reduce its speed nor can magic displace it against its will, such as with the Vortex Warp spell. Additionally, if the valstrax flies at least 80 ft. in a straight line, it can cast the plane shift spell (DC 24) as an action before the end of that turn.

Unusual Nature. The valstrax doesn’t require air.

Weakness Exploitation. When the valstrax has advantage on an attack rolls and it hits a target, its attack deals its maximum damage if the lower of the two d20 rolls would also hit the target (all extra damage dice must still be rolled).

Multiattack. The dragon makes two Bite attacks, two Tail attacks, and three Wing attacks. It can replace any attack for a Dragonbolt attack and/or any two attacks for any other available action at its disposal.

Bite. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 6) piercing damage.

Wing. Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: 24 (4d8 + 6) piercing damage plus 9 (2d8) necrotic damage. If this attack hits a prone target, the target takes an extra 27 (6d8) necrotic damage.

Tail. Melee Weapon Attack: +15 to hit, reach 30 ft., one target. Hit: 15 (2d8 + 6) piercing damage plus 9 (2d8) necrotic damage and the target can't take reactions until the end of the valstrax's next turn.

Dragonbolt. Ranged Weapon Attack. +18 to hit, reach 120/320 ft., one target. Hit: 16 (4d8) necrotic damage plus 17 (3d8 + 9) bludgeoning damage. If a target is hit by this attack twice in one turn, its subjected to the effects of the Disintegrate spell (DC 26).

Bow Shock (Mythic). The valstrax focuses its debris at a point it chooses within 30 feet of it then causes the debris to burst in a 20-foot-radius sphere centered on that point. Each creature of the dragon’s choice in the area must make a DC 25 Constitution saving throw. On a failed save, the creature’s speed is halved and it has disadvantage on attack rolls until the end of the valstrax's next turn.

Crimson Salvo. The valstrax fires six draconic energy balls at up to 6 targets within 60 feet of it. A target must make a DC 26 Dexterity saving throw, taking 27 (6d8) necrotic damage on a failed save or half as much damage on a successful one. A creature targeted by 2 or more energy balls must make a saving throw for each one, and if the creature fails 2 or more of these saving throws, a Destructive Wave bursts from its location (necrotic only, DC 25). If the creature was on the ground, the energy remains in a 15-foot squared area centered on a point where the target was standing when the attack was made. At the start of the valstrax's next turn each creature in that area takes 9 (2d8) necrotic damage. In addition, once before the end of the valstrax's next turn, when it takes damage, it can use its reaction to make two Dragonbolt attacks.

Risen Twister (Recharge 5–6). The Valstrax charges up then spins around like a blender, with its wings acting like blades. Each creature in a 20-foot-radius, 40-foot-high cylinder centered on the valstrax must make a DC 26 Dexterity saving throw, taking 24 (4d8 + 6) slashing damage plus 9 (2d8) necrotic damage and be pushed up to 10 feet away and knocked prone on a failed save, or half as much damage be pushed 10 feet away and isn't knocked prone on a successful one. If 3 or more creatures fail the saving throw, a Circle of Death (7th level, DC 25) emits from the valstrax's location.

Crimson Star Beam (Recharge 5–6). The valstrax positions its wings in front of it to release accumulated draconic energy in a 120-foot line that is 10-feet wide. Each creature in that line must make a DC 26 Dexterity saving throw, taking 70 (20d6) necrotic damage on a failed save or half as much damage on a successful one. The valstrax fires two of these beams but they cannot overlap.  

In addition, if the valstrax's Star of Despair trait has activated in the past hour, the beam also unleashes a barrage of meteors that deals an additional 35 (10d6) bludgeoning damage and 35 (10d6) fire damage on a failed save or half as much damage on a successful one, and the valstrax's debris ignites. Until the start of the valstrax's next turn, whenever a creature other than the valstrax enters the area for ignited debris the first time or starts its turn there, it takes 5 (1d10) necrotic damage and 5 (1d10) fire damage.

Stellar Shower Ambush (2/Per Long Rest). The valstrax flies 1000 feet into the air without provoking opportunity attacks before showering the area below it with draconic orbs. Each creature within 60 feet of the space the valstrax left must make a DC 26 Dexterity saving throw, taking 54 (12d8) necrotic damage on a failed save, or half as much damage on a successful one.

On its subsequent turn, the valstrax must use its action to slam into the ground in a space within 300 feet of its starting location. Each creature in a 30-foot radius sphere centered on the valstrax must make a DC 26 Dexterity saving throw, taking 112 (32d6) necrotic damage on a failed save, or half as much damage on a successful one.

Throttle (1/Round). The valstrax takes the dash action.

The Valstrax 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 Valstrax regains spent legendary actions at the start of its turn.

Jet Uppercut. The valstrax makes a Wing attack with advantage.

Detect. The valstrax makes a Wisdom (Perception) Check.

Rocket Dash (Costs 2 Actions). The valstrax moves up to half its fly speed in a straight line. During this move it can move through other creatures. Each creature the valstrax moves through must succeed on a DC 26 Dexterity saving throw or take 24 (4d8 + 6) slashing damage plus 9 (2d8) necrotic damage and are knocked prone on a failed save. On a successful save, the target takes half damage and is not knocked prone.

Risen Twister (Costs 2 Actions). The valstrax recharges its Risen Twister and/or uses it.

Ground Zero Burst (Costs 2 Actions). The valstrax releases draconic energy in a 15-foot radius around it. Each creature in that area must make a DC 26 Dexterity saving throw, taking 31(2d8) necrotic damage on a failed save or half as much damage on a successful one.

If the Valstrax's "Star of Despair" trait has been activated in the past hour, it can use the following options as legendary actions:

Meteor Barrage. The valstrax makes 1d6 + 1 Dragonbolt attacks.

Twin Tail. The valstrax makes a tail attack. If the attack misses, it can make another tail attack as part of the same legendary action.

Crimson Salvo (Costs 2 Actions). The valstrax uses its Crimson Salvo.

Shooting Star (Costs 2 Actions). The valstrax moves up to twice its speed in a straight line; if the valstrax is grappled, it automatically breaks the grapple at the start of this movement. Each creature in the line takes 12 (3d8) thunder damage and must make a DC 23 Strength saving throw. A creature under the effects of the valstrax's Bow Shock has disadvantage on this saving throw. On a failure, a creature takes 24 (4d8 + 6) bludgeoning damage plus 12 (3d8) necrotic damage and is flung up to 20 feet away from the valstrax's path and knocked prone. On a success, the creature takes half as much bludgeoning damage and isn’t flung away or knocked prone.

Crimson Star Beam (Costs 3 Actions). The valstrax recharges its Crimson Star Beam and uses it.