Ancient Silver Dragon

The dragon suffers no harmful effects from high altitudes. When flying at high altitude, the dragon can, after 1 minute of concentration, discorporate into clouds. In this form, it has advantage on Stealth checks, its fly speed increases to 300 feet, it is immune to all nonmagical damage, it has resistance to magical damage, and it can't take any actions except Hide. If it takes damage or descends more than 500 feet from where it transformed, it immediately returns to its corporeal form. The dragon can revert to its true form as an action.

The dragons spellcasting ability is Charisma (save DC 23). It can innately cast the following spells, requiring no material components.
- 3/Day Each: Charm Person, Faerie Fire, Awaken, Geas
- 1/Day: Heroes Feast, Telepathic Bond

When the dragon fails a saving throw, it can choose to succeed instead. When it does, some of its scales dissipate into clouds. If it has no more uses of this ability, its Armor Class is reduced to 20 until it finishes a long rest.

Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 32 (4d10 + 10) piercing damage plus 9 (2d8) cold damage.

The dragon uses one of the following breath weapons:

The dragon magically takes the shape of a humanoid or beast or changes back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (dragons choice). In the new form the dragons stats are unchanged except for its size. It can't use Spit Frost Breath Weapons Tail Attack or Wing Attack except in dragon form. In beast form it can attack only with its bite and claws if appropriate to its form. If the beast form is Large or smaller the reach of these attacks is reduced to 5 feet. In humanoid form it can attack only with its rapier.

Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 23 (3d8 + 10) slashing damage.

The dragon exhales freezing wind in a 90-foot cone. Each creature in the area makes a DC 24 Constitution saving throw taking 90 (20d8) cold damage on a failed save or half damage on a success. On a failure the creature is also slowed until the end of its next turn.

The dragon attacks with its bite and twice with its claws. In place of its bite it can use Spit Frost.

The dragon exhales paralytic gas in a 90-foot cone. Each creature in the area must succeed on a DC 24 Constitution saving throw or be paralyzed until the end of its next turn.

Melee Weapon Attack: +17 to hit, reach 5 ft., one target. Hit: 14 (1d8 + 10) piercing damage.

The dragon targets a creature within 60 feet forcing it to make a DC 24 Constitution saving throw. The target takes 22 (4d10) cold damage on a failure or half damage on a success. On a failure the creatures Speed is also halved until the end of its next turn. Flying creatures immediately fall unless they are magically kept aloft.

Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 23 (3d8 + 10) bludgeoning damage and the dragon pushes the target 10 feet away.

When a creature the dragon can see within 10 feet hits the dragon with a melee attack, the dragon makes a tail attack against it.

Each creature of the dragons choice within 120 feet that can hear it makes a DC 21 Charisma saving throw. On a failure, it is frightened for 1 minute. A creature repeats the saving throw at the end of its turns, ending the effect on itself on a success. When it succeeds on a saving throw or the effect ends for it, it is immune to Roar for 24 hours.

Only one legendary action can be used at a time and only at the end of another creatures turn. It regains spent legendary actions at the start of its turn.

Pounding winds surround the dragon in a 20-foot radius. A creature in this area attempting to move closer to the dragon must spend 2 feet of movement for every 1 foot closer it moves, and ranged attacks against the dragon are made with disadvantage. A creature that starts its turn in the windstorm makes a DC 24 Constitution saving throw, taking 11 (2d10) cold damage on a failure. The windstorm lasts until the start of the dragons next turn.

The dragon beats its wings. Each creature within 15 feet makes a DC 25 Dexterity saving throw. On a failure, it is pushed 10 feet away and knocked prone. The dragon can then fly up to half its fly speed.