True Dragon's Breath

You bring forth a torrent of elemental energy comparable to a true dragon's breath weapon.

When you cast this spell, you produce a 15ft cone of your choice of acid, cold, fire, lightning, or poison energy. Each creature in that area must make a Dexterity saving throw, taking 7d6 damage of the chosen type on a failed save, and half as much on a successful one.

If you cast this spell with a 5th or 6th level spell slot, the damage increases to 11d6 and the cone's range increase to 30ft. If you cast this spell with a 7th or 8th level spell slot, the damage increases to 18d6 and the cone's range increases to 60ft. If you cast this spell using a 9th level spell slot, the damage increases to 26d6 and the cone's range increases to 90ft.