You bring forth a torrent of true elemental energy from your ancestral line, using your breath weapon

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. The chosen damage type ignores all resistances and immunity.

Fire ignites any flammable objects in the area that aren't being worn or carried.