The dragon sees normally through light or heavy obscurement caused by fog, mist, clouds, or high wind.

If the dragon fails a saving throw, it can choose to succeed instead.

The dragon has advantage on saving throws against spells and other magical effects.

The dragon’s movement is never impeded by difficult terrain, and its speed can’t be reduced by spells or magical effects. It can’t be restrained (per the condition), and it escapes automatically from any nonmagical restraints (such as chains, entanglement, or grappling) by spending 5 feet of movement. Being underwater imposes no penalty on its movement or attacks.

Gale-force winds rage around the dragon, making it immune to ranged weapon attacks except for those from siege weapons.

on initiative count 20 (losing initiative ties), the dragon takes a lair action to generate one of the following effects; the dragon can’t use the same effect two rounds in a row.

• Sand and dust swirls up from the floor in a 20-foot radius sphere within 120 feet of the dragon at a point the dragon can see. The sphere spreads around corners. The area inside the sphere is lightly obscured, and each creature in the sphere at the start of its turn must make a successful DC 15 Constitution saving throw or be blinded for 1 minute. A blinded creature repeats the saving throw at the start of each of its turns, ending the effect on itself with a success.

• Fragments of ice and stone are torn from the lair’s wall by a blast of wind and flung along a 15-foot cone. Creatures in the cone take 18 (4d8) bludgeoning damage, or half damage with a successful DC 15 Dexterity saving throw.

• A torrent of wind blasts outward from the dragon in a 60-foot radius, either racing just above the floor or near the ceiling. If near the floor, it affects all creatures standing in the radius; if near the ceiling, it affects all creatures flying in the radius. Affected creatures must make a successful DC 15 Strength saving throw or be knocked prone and stunned until the end of their next turn.