Prerequisite: Viashino

When you take the Attack action, you can replace one of your attacks with an exhalation of fire in a 15-foot cone. Each creature in the area must make a Dexterity saving throw against DC equal to 8 + your Constitution modifier + your proficiency bonus. A creature takes 1d10 fire damage on a failed save, and half as much damage on a successful one. This damage increases by 1d10 when you reach 5th level (2d10), 11th level (3d10), and 17th level (4d10).

You can use this trait a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.