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

Multiattack. Zethraakx makes four attacks, two with its claws, one with its bite, and one with its tail.

Bite. Melee Weapon Attack: +14 to hit, reach 10ft., one target. Hit: 24 (3d10 + 8) piercing damage plus 14 (4d6) stance elemental damage. 

Claw. Melee Weapon Attack: +14 to hit, reach 15ft., one target. Hit: 19 (3d6 + 8) slashing damage.

Tail. Melee Weapon Attack: +14 to hit, reach 20ft., one target. Hit: 22 (3d8 + 8) bludgeoning damage. On a hit, the target must make a DC 22 Strength saving throw or be knocked prone.

Ice Storm. Zethraakx magically creates a hail of rock-hard ice that pounds to the ground in a 20-foot-radius, 40-foot-high cylinder centered on a point within 150 feet. Each creature in the cylinder must make a DC 21 Dexterity saving throw. A creature takes 17 (3d10) bludgeoning damage and 17 (3d10) slashing damage on a failed save, or half as much damage on a successful one.

Lightning Storm. Zethraakx magically creates three bolts of lightning, each of which can strike a target Zethraakx can see within 120 feet of it. A target must make a DC 23 Dexterity saving throw, taking 22 (4d10) lightning damage on a failed save, or half as much damage on a successful one.

Flame Storm. Zethraakx magically creates a vertical column of fire roars down from the heavens in a location you specify. Each creature in a 10-foot-radius, 40-foot-high cylinder centered on a point within 40 feet of Zethraakx must make a DC 21 Dexterity saving throw, taking 27 (6d8) fire damage on a failed save, or half as much damage on a successful one.

Breath Weapons (Recharge 5-6). Zethraakx uses one of the following breath weapons depending on his stance.

Lightning Breath. Zethraakx exhales lightning in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 22 Dexterity saving throw, taking 55 (10d10) lightning damage on a failed save, or half as much damage on a successful one.

Cold Breath. Zethraakx exhales an icy blast in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 54 (12d8) cold damage on a failed save, or half as much damage on a successful one.

Fire Breath. Zethraakx exhales fire in a 90-foot cone. Each creature in that area must make a DC 22 Dexterity saving throw, taking 56 (16d6) fire damage on a failed save, or half as much damage on a successful one.

Stance Switching. As a bonus action, Zethraakx can switch between three different stances, each giving him access to a different breath weapon, bite elemental damage, and resistances/immunities.

• Flame: Fire breath weapon, added fire damage to the bite attack, immunity to fire damage, and resistance to cold damage.
• Storm: Lightning breath weapon, added lightning damage to the bite attack, immunity to lightning damage, and resistance to fire.
• Cold: Cold breath weapon, added cold damage to the bite attack, immunity to cold damage, and resistance to lightning damage.

Overcharge. When Zethraakx is dealt cold, fire, or lightning damage and isn't immune or resistant to the damage, roll a d20. On a roll of 10 or lower, roll a d6 to recharge Zethraakx's breath weapon. The breath weapon can only be recharged on a 6 this way. On a roll of 11 or higher, roll a d6. On a 1, Zethraakx uses its Cold Storm ability. On a 3, Zethraakx uses its Lightning Storm ability. On a 5, Zethraakx uses its Flame Storm ability.

Zethraakx 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. Zethraakx regains spent legendary actions at the start of its turn.

Attack. Zethraakx makes a Bite attack.

Storm (Costs 2 Actions). Zethraakx uses a storm ability, roll a d6.

• 1-2: Ice Storm
• 3-4: Lighting Storm
• 5-6: Flame Storm

Tail Sweep (Costs 3 Actions). Zethraakx sweeps its tail and rises into the air. Each creature within 30 feet of the Zethraakx must succeed on a DC 20 Strength saving throw, taking 28 (5d10) bludgeoning damage and are knocked prone on a failed save. On a successful save the target takes half damage and isn't knocked prone. The Zethraakx can then rise 30 feet into the air.