Echo of the Skybound

Echo of the Skybound:

Once per long rest, you can cast the Dragon's Breath Weapon trait. (Force Damage Only) 

Your voice momentarily takes on Vaeryn’s tone, and your eyes shimmer with dragon light. 

Breath Weapon:

When you take the Attack action, you can replace one of your attacks with an exhalation of a magical energy in a 30-foot line that is 5 feet wide. Each creature in the area must make a Dexterity saving throw against a DC equal to 8 + your Constitution modifier + your proficiency bonus. A creature takes 2d8 damage of force damage on a failed save, and half as much damage on a successful one.

This damage increases by 1d8 when you reach 5th level (3d8), 11th level (4d8), and 17th level (5d8).