Breath Weapon

As an action, you can exhale destructive energy in a 15-foot cone (or a 5-by-30-foot line for lightning ancestries). Each creature in the area makes a Dexterity saving throw (DC 8 + your Constitution modifier + your proficiency bonus), taking 2d10 damage of the associated type on a failed save, half as much on a success. The damage increases at higher levels. You can use this trait a number of times equal to your proficiency bonus, regaining all expended uses when you finish a Long Rest.