When you take the Attack action on your turn, you can replace one of your attacks with an exhalation of magical energy in a 15-foot cone. Each creature in that area must make a Dexterity saving throw (DC = 8 + your Constitution modifier + your proficiency bonus). On a failed save, the creature takes an amount of damage equal to 2d4 + your Constitution modifier of the damage type associated with your Gem Ancestry. On a successful save, it takes half as much damage. This damage increases by 2d4 when you reach 5th level (4d4), 9th level (6d4), 13th level (8d4), and 17th level (10d4). You can use your Breath Weapon a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.