Draconic Firestorm

You evoke the power of the dragon to unleash a massive firestorm upon your enemies. A roar erupts from your mouth as you gather your energy and release it in a fiery burst. The spell creates a 40-foot radius sphere of flames that you can see within range.

All creatures within the area of effect must make a Dexterity saving throw. A creature takes 10d6 fire damage on a failed save, or half as much damage on a successful one. In addition, creatures with the Dragon type fail this saving throw automatically.

Additionally, you may choose to imbue the firestorm with the power of a specific type of dragon. If you choose to do so, the fire damage dealt by the spell is changed to that type of damage (acid, cold, fire, lightning, or poison) for the duration of the spell. The type of dragon you choose determines the damage type.

When you cast this spell using a spell slot of 7th level or higher, the damage dealt by the firestorm increases by 1d6 for each level above 6th.