Path of the Platinum Guardian

Most Dragonborn barbarians are fueled by a rage that burns within them, but some are inspired into this rage through their intense connection to the Platinum Dragon. These barbarians believe that through their unfettered battle lust, they are allowing the Platinum Dragon's power to flow through them, guiding them in combat and unlocking primal magic, drawn from the deep roots of their Dragon Ancestry.

Platinum Guardians are elite Dragonborn soldiers chosen at birth to protect their cities and temples to the Platinum Dragon. They train intensely and, when they come of age, undergo a ritualistic ceremony, during which a portion of their belly scales are cut away over their heart and they are branded with an elemental sigil. This sigil is the activator of their rage and source of their primal power.

Elemental Aura

When you select this path at 3rd level, you emanate a magical, elemental aura while you rage. The aura extends 10 feet from you in every direction, but not through total cover.

Your aura has an effect that activates when you enter your rage, and you can activate the effect again on each of your turns as a bonus action. Choose Acid, lightning, Fire, Poison, or cold based on Draconic Ancestry.

If your aura's effects require a saving throw, the DC equals 8 + your proficiency bonus + your Constitution modifier.

Acid

When this effect is activated, the ground beneath you becomes a roiling puddle of acid. All other creatures within your aura take 1d4 acid damage at the beginning of their turn. This effect lasts for 1 round or until the creature moves out of the acid. The acid puddle does not move with you, and will fade if you leave the space you cast it from. When you reach level 6 the effect will remain for 2 rounds even if you leave the point of origin and will remain for 3 rounds at level 12, and 4 rounds at level 18. 

Cold

When this effect is activated, up to 2 creatures you can see in your aura must make a constitution saving throw. Upon a failed save, they become chilled, reducing their movement by 10ft for the rest of the round and they suffer 1d4 cold damage. On a successful save, their movement speed is not affected and they take half damage. The number of creatures you can target increases to 3 at 6th level, 4 at 12th level, and 5 at 18th level. 

Fire

When this effect is activated, all other creatures in your aura take 2 fire damage each. The damage increases when you reach certain levels in this class, increasing to 3 at 6th level, 4 at 12th level, and 5 at 16th level.

Lightning

When this effect is activated, you can choose one other creature you can see in your aura. The target must make a Dexterity saving throw. The target takes 1d4 + CHA lightning damage on a failed save, or half as much damage on a successful one. The number of creatures you can target increases to 2 at 6th level, 3 at 12th level, 5 at 18th level.

Poison

When this effect is activated, a noxious fog surrounds the head of one creature you can see in your aura and they must make a constitution saving throw. On a failed save they suffer 1d4 poison damage and become blind for one round, or resist the blindness and take half damage on a successful save. The cloud will stay around the target's head for one round or until they move out of it. The number of creatures you can target increases to 2 at 6th level, 3 at 12th level, 5 at 18th level.

Intimidating Presence

Your prowess in battle gives you an intimidating presence, making your enemies hesitant to attack you in battle.

Starting at level 6, the first time you rage in combat all enemies you can see within 10 feet must make a WIS saving throw or they are frightened of you for one round.

Platinum Roar

Your experience as a soldier has taught you to bring out the best in those who fight alongside you.

At level 10, as a bonus action while you are raging you release an invigorating battle cry, granting a number of allies you can see equal to your charisma modifier advantage on their next attack. You may activate this ability twice per long rest.

Divine Beast

The Platinum Dragon ignites the primal rage of your draconic ancestors, awakening a bestial power within you.

At 14th level you may activate this ability once per long rest. While raging, at the beginning of your turn you may as an action choose to become a divine beast. You immediately drop your weapons and adopt a bestial posture, gaining an extra 15ft of movement as well as a bite attack (1d10 + STR + 10 elemental damage from Draconic Ancestry) and 2 claw attacks (1d6 + STR + 3 elemental damage from Draconic Ancestry each).

You have advantage on your first bite attack after activating this ability. You remain in the form of a divine beast for 5 rounds, even if your rage ends before the 5 rounds are up. Due to your bestial form, you cannot use items without assistance from another party member (ex, a party member can feed you a potion, but you cannot use it on yourself). Once the 5 rounds are up your bestial form reverts back to normal and you gain 2 levels of exhaustion.