Ancient Lunar Dragon (Homebrew)

Innate Spellcasting. The dragon's spellcasting ability is Charisma (spell save DC 22, +14 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

At will: darkness, pass without trace, shield, mirror image, hunter's mark, moonbeam

1/day each: ravenous void, true polymorph, blade of disaster, foresight, invulnerability, psychic scream

Legendary Resistance. If the dragon fails a saving throw, it can choose to succeed instead. If it uses this feature again before the next dawn, it loses 29 hitpoints. Each time it uses this feature again before the next dawn, the hitpoint loss increases by 29.

Magic Weapons. The dragon's natural weapon attacks are considered +4 adamantine weapons.

Night Shadow. When the dragon is in dim light or darkness, it has advantage on stealth checks and it's speed is doubled. Additionally all of it's attacks deal maximum damage, and deal force damage rather than bludgeoning, piercing, or slashing (Included in attack).

Reflective Carapace. Any time the dragon is targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 5, the dragon is unaffected. On a 6, the dragon is unaffected, and the effect is reflected back at the caster as though it originated from the dragon turning the caster into the target.

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +22 to hit, reach 15 ft., one target. Hit: 30 (3d10 + 14) piercing damage. When in dim light or darkness, this attack instead does 44 force damage, or 74 on a critical hit.

Claw. Melee Weapon Attack: +22 to hit, reach 10 ft., one target. Hit: 24 (3d6 + 14) slashing damage. When in dim light or darkness this attack instead does 32 force damage, or 50 on a critical hit.

Tail. Melee Weapon Attack: +22 to hit, reach 20 ft., one target. Hit: 27 (3d8 + 14) bludgeoning damage. When in dim light or darkness, this attack instead does 38 force damage, or 62 on a critical hit.

Frightful Presence. Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 22 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Breath Weapons (Recharge 5–6). The dragon uses one of the following breath weapons:

Force Breath. The dragon lets out a blast of force in a 90-foot cone. Each creature in that area takes 60 force damage.

Sleep Breath. The dragon exhales sleep gas in a 90-foot cone. Each creature in that area must succeed on a DC 25 Constitution saving throw or fall unconscious for 10 minutes. This effect ends for a creature if the creature takes damage or someone uses an action to wake it.

Change Shape. The dragon magically polymorphs into a humanoid or beast that has a challenge rating no higher than its own, or 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 (the dragon's choice).

In a new form, the dragon retains its alignment, hit points, Hit Dice, ability to speak, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form.

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The dragon regains spent legendary actions at the start of its turn.

Detect. The dragon makes a Wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 15 feet of the dragon must succeed on a DC 26 Dexterity saving throw or take 20 (3d6 + 10) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.

Rampage (Costs 3 Actions). The dragon moves up to half it's speed and then makes three claw attacks.