High Fliers. The dragon can breathe in any area that has an amount of air, no matter how thin. It can hold its breath for up to ten minutes at a time.

Verdant Scales. The dragon's flight speed is doubled while in clean air. Also while in clean air, if the dragon moves at least 40 feet in a straight line before attacking, the attack deals an additional 11 (3d6) damage. Effects, climates, or conditions which pollute or exist instead of air; including but not limited to volcanic eruptions, the Fog Cloud spell, the smoke of a forest fire, and the dragon being underwater are considered to not be clean air for the purposes of this trait.

Fade Into Fog. The dragon can use its action to shapechange into a mass of semisolid air (or back to its dragon form). While in this form, the dragon makes stealth checks at advantage and loses its walking and swimming speeds, but gains the hover property.

Spellcasting. The dragon is an innate spellcaster. Its spellcasting ability is Charisma (spell save DC 13, +5 to hit with spell attacks). The dragon knows the following spells and can cast them without material or somatic components:
Cantrips (at will): Lightning Lure, Shocking Grasp
1x/day: Witch Bolt

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

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 11 (1d10 + 5) piercing damage plus 5 (1d8) lightning damage.

Tail. Melee Weapon Attack: +8 to hit, reach 10ft. , one target. Hit. 12 (1d12+5) bludgeoning damage.

Cloud Breath. The dragon exhales a dark storm of clouds in a 30­-foot long, 5-foot wide line. Each creature in that line must make a DC 14 Dexterity saving throw, taking 49 (11d8) lightning damage on a failed save, or half as much damage on a successful one.

Dash (2x/day). The dragon takes the dash action as a bonus action.