Elemental Shifting. As a reaction when the dragon takes damage, it can shift its elemental affinity to the damage type, gaining immunity to that type until the end of its next turn. Additionally, its breath weapon changes to the chosen damage type until the end of its next turn. The available damage types are acid, cold, fire, lightning, and thunder.

Innate Spellcasting. The dragon's innate spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). It can cast the following spells, requiring no material components:

• At will: detect magic, feather fall, message
• 3/day each: misty step, wall of fire
• 1/day each: control water, investiture of flame

Legendary Resistance (3/day). If the dragon fails a saving throw, it can choose to succeed instead.

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: +10 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 5) piercing damage plus 5 (1d10) damage determined by the dragon's current elemental affinity.

Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.

Tail. Melee Weapon Attack: +10 to hit, reach 15 ft., one target. Hit: 14 (2d8 + 5) slashing damage.

Elemental Breath (Recharge 5–6). The dragon exhales destructive energy in a 60-foot cone. Each creature in that area must make a DC 15 Dexterity saving throw, taking 49 (14d6) variable damage on a failed save, or half as much damage on a successful one. The damage type is based off of the dragons current elemental affinity.