Multiattack. Vuuthramis makes three attacks: one with its bite and two with its claws.
Bite.Melee Weapon Attack:+8 to hit, reach 10 ft., one target. Hit:16 (2d10 + 5) piercing damage.
Claw.Melee Weapon Attack:+8 to hit, reach 5 ft., one target. Hit:12 (2d6 + 5) slashing damage.
Breath Weapons (Recharge 5–6). Vuuthramis uses one of the following breath weapons.
Vuuthramis exhales lightning in a 60-foot line that is 5 feet wide. Each creature in that line must make a DC 15 Dexterity saving throw, taking 55 (10d10) lightning damage on a failed save, or half as much damage on a successful one.
Vuuthramis exhales repulsion energy in a 30-foot cone. Each creature in that area must succeed on a DC 15 Strength saving throw. On a failed save, the creature is pushed 40 feet away from the dragon.