Due to the unique souls of Dragonborn, they are able to cultivate the focus of their souls into dangerous fighting forces. For white Dragonborn, they strive to embody the vast bitterness of a winter storm.

Stalwart Frost

When you choose this archetype at 3rd level, you gain the ability to cover yourself in a dense frost as a bonus action adding your proficiency bonus to your AC for one minute. For the duration of the effect any creature that hits you with a melee attack or would hit you without the AC bonus takes cold damage equal to your constitution modifier times your proficiency bonus. This can be used a number of times equal to your proficiency bonus and resets on a long rest.

At level 20 also add your Constitution bonus to your bonus AC at level 20.

Empowered Breath Weapon

Starting at 7th level, you can empower your breath weapon with the force of your soul. This increases the damage to 6d6 and doubles the range to a 30ft cone. If a creature fails the Constitution saving throw (DC 10 + your Constitution modifier + your proficiency bonus) they are encased in ice and have their speed reduced to 0 until the end of your next turn taking half damage and halving their speed until the end of your next turn on a successful save. An encased creature can be broken free by succeeding a Strength saving throw (DC 10 + your Constitution modifier + your proficiency bonus) on their turn or by taking bludgeoning or fire damage equal to or greater than the amount of cold damage dealt by your attack. This can be used a number of times equal to your proficiency bonus and resets on a long rest but must recharge on 5-6 on a d6 before another use.

Damage increases by 1d6 and the number of rounds a creature is encased or slowed is increased by 1 at levels 10, 15, 18, and 20.

Icy Body

At 10th level you gain +1 to your AC and can freeze the water beneath your feet as you walk across.

Frozen Aura

at level 15, the temperature in a 20ft radius sphere around you drops dramatically, reducing the movement speed of everyone inside the sphere by 10ft and any creature that starts or ends a turn inside the aura takes 3d6 cold damage. This can be activated as a bonus action once per short rest and lasts one minute.

Frozen Heart

At level 18, on a critical hit you deal an extra 4d6 cold damage and your opponent's speed is halved until the end of your next turn. You score a critical hit on 19-20.