True Dragonborn

You descent directly from a Dragon, and your draconic heritage grows on you as you become stronger. You manifest the following abilities:

• Increase your Strength, Constitution, or Charisma by 1, to a maximum of 20.
• Your scales harden. While you aren't wearing armor, you can calculate your AC as 13 + your Dexterity modifier. You can use a shield and still gain this benefit.
• Your lungs become stronger. You can use your Breath Weapon 1 additional time per short or long rest.