Crystal dragon ancestry: Crystal Dragonborn trace their ancestry to a Crystal Dragon, granting them a magical affinity for radiance.

Breath weapon: When Crystal Dragonborn take the Attack action on their turn, they can replace one of their attacks with an exhalation of magical energy in a 30-foot line that is 5 feet wide. Each creature in that area must make a Dexterity saving throw (DC = 8 + Constitution modifier + proficiency bonus). On a failed save, the creature takes 1d10 radiant damage. On a successful save, it takes half as much damage. This damage increases by 1d10 when they reach 5th level (2d10), 11th level (3d10), and 17th level (4d10). They can use their Breath Weapon a number of times equal to their proficiency bonus, and they regain all expended uses when they finish a long rest.

Draconic resistance: Crystal Dragonborn have resistance to radiant damage.

Psionic mind: Crystal Dragonborn can telepathically speak to any creature they can see within 30 feet of themselves. They don’t need to share a language with the creature, but the creature must be able to understand at least one language.

Gem flight: Starting at 5th level, Crystal Dragonborn can use a bonus action to manifest spectral wings on their body. These wings last for 1 minute. For the duration, they gain a flying speed equal to their walking speed and can hover. Once they use this trait, they can’t do so again until they finish a long rest.