Amphibious. The dragon can breathe air and water.

Mount. Can be used as mount, must make a successful animal handling roll of DC 15 to mount this dragon successfully each time a character wants to utilize this ability.

Legendary Resistance (1/Day). If the dragon fails a saving throw, it can choose to succeed instead.

Multiattack. The dragon makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 7) piercing damage plus 8 (2d6) force damage plus 5 (2d4) acid damage.

Claw. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 12 (2d8 + 7) slashing damage.

Breath Weapon (Recharge 4–6). The Dragon uses one of the following breath weapons.

Twilight Devastation Breath. The dragon exhales a wave of necrotic and acid energy in a 60-foot cone. Each creature in that cone must make a DC 20 Dexterity saving throw, taking 22 (4d10)  acid damage and 38 (6d12) radiant damage on a failed save, or half as much damage on a successful one.

Lesser Exalted Breath. The dragon exhales the restoring winds of Mount Celestia in a 30-foot cone. Each creature in that area of the dragon's choice regains 35 (6d10) hit points, and each creature in that area of the dragon's choice that has been dead for no longer than 1 hour is restored to life with 1 hit point.