Path of the Dragon Cursed

Background

    Firstly, the background for you barbarian is very important because it will determine aspects of your abilities, features, temperament, and appearance. What type of dragon has cursed your bloodline? Was it a fire breathing brass dragon, a poison spewing green dragon, or maybe it was a mighty blue dragon with its lightning breath. Depending on the Dragon who has cursed you, at first level you gain resistance to their main damage type and in the case of green dragon’s curse you are immune to the poisoned status effect. In particularly unique instances you may have been cursed by an atypically dragon such as a dracolich or a  shadowfell corrupted dragon, giving you resistance to necrotic damage despite it not being a elemental damage type. 

    How did your blood line become cursed. Perhaps you or one of your ancestors stole from a dragons hoard, killed many of its followers, or maybe even killed the dragon itself. In a act of retribution, possibly at the expense of its life and soul, it curses you and your bloodline to an eternal rage, that if left unchecked, will cause you to harm or kill anyone you love or care about at the drop of a hat. Those cursed this way, often are haunted by visions and dreams of said dragon, goading them to commit atrocities, threatening them, and belittling their feelings, intentions, and opinions. For flavor, the player can role a wisdom saving through to see if they manage to sleep through the night, or withstand a traumatic event without succumbing to their visions. On a 11 or above the succeed, on a 5 to 10 they are plagued by their visions and if awake are stunned for one round, on a 2 to 4 gain a point of exhaustion, and on a 1 or critical failure they wake and enter their draconic rage.  
  On the other hand, perhaps you are the descendant of a dragon itself. In such a case, though you may still be cursed by visions and nightmares, this curse doesn’t have the malevolence of a dragons wrath behind it. Rather, if your ancestor still lives, they may care deeply for you and feel great guilt for your suffering. In the case of such a background, you likely have some visible feature of you your draconic bloodline, such as scales along your arms legs or spine, claws instead of fingernails (giving you a +1 to unarmed melee attacks), or perhaps something as simple as dragon like eyes. It is up to you and your DM how obvious it is to others that you have draconic lineage.

Draconic Rage

Whenever you enter rage you must role a d20. If you role a 20 you enter your draconic rage, a state where you gain resistance to all elemental damage (fire, ice, poison, acid, lightning, and thunder) and can maintain this rage state until your next short or long rest. Your main draconic damage type resistance now becomes a immunity for the duration of your rage. While in Draconic Rage, you are immune to fear and charm effects. This can provide such warriors great advantage on the battlefield, but it comes with some serious drawbacks. In this state, all your attacks must be reckless and the must all be melee. Also, all attacks must be made on the closest target to you at the moment or a creature who has attacked you within the last round of combat. This includes any and all creatures you view as allies. To break your draconic rage you must either be knocked unconscious or succeed ad wisdom saving through (DC 15). If you, within 1 round, attack an ally recognize as a close friend ( ie. mate, spouse, child, or friend known for at least 6 or more months) you get advantage on your saving through.

At level 6, to drop draconic rage your DC is now 12.
At level 10, to drop draconic rage your DC is now 8. 
At level 14, to drop draconic rage your DC is now 4.

Controlled Draconic Rage

Now when you role your D20 to enter rage, if you role a 19 you enter a controlled Draconic Rage. In this state you have all the aspects of Draconic Rage, but you are not forced to attack your allies. Now, you can also attempt to drop Draconic Rage into Controlled Draconic Rage by rolling a wisdom saving throw (DC18).

At level 10, you can enter Controlled Draconic Rage on a 17 to 19 and the wisdom saving throw DC to drop Draconic Rage to Controlled Draconic Rage is now 14.
At level 14, you can enter Controlled Draconic Rage on a 12 to 19 and the wisdom saving throw DC to drop Draconic Rage to Controlled Draconic Rage is now 10.
At level 18, you can enter Controlled Draconic Rage on a 6 to 19 and the wisdom saving throw DC to drop Draconic Rage to Controlled Draconic Rage is now 5.

Fury of the Elements

You mastery over you curse has increased. You can now call upon its power when attacking in your draconic rage to give you Elemental Fury, making all attacks deal 1D6 damage of your element type. You, also apply a status effect based off your element type if they fail a associated saving throw equal to 8 + your strength modifier + your proficiency bonus. Status effects include:

Fire + Dex saving throw = Status on fire until action taken to put out fire

Lightning + Con or Dex saving trow = Status stunned for one round

Ice/Cold + Con saving throw = Status Slowed (moves half speed, can only take action or bonus action, a spell that takes a action to cast is not released until your next round, and can only make one attack per attack action) until DC 15 constitution saving throw is passed at end of their turn

Poison/Acid + Con saving throw = Status Poisoned

Necrotic/Radiant + Wisdom saving throw = Status Weakened (deals halve damage with all attacks) until DC 15 constitution saving throw is passed at end if their turn

You can now as well for your action now cast the Elemental Fury cantrip. Said cantrip hits the intended target within 60 feet of you if you beat its AC. Your spellcasting modifier for this attack is your constitution so on attack role a D20 + Con Modifier + your proficiency bonus. Damage dealt is 1D6 + Con Modifier + Proficiency bonus. If in your Draconic Rage, you can still use your cantrip despite it being a ranged attack and you can double your damage die and apply your associated status effect.

At level 10, your Elemental Fury melee attacks deal extra D8 instead of a D6 and your Elemental Fury Cantrip deals 2 D6 now.

At level 14, your Elemental Fury melee attacks deal extra D12 instead of a D6 or D8 and your Elemental Fury Cantrip deals 2 D10 now.

Dragon’s Blast

Drawing on the power of your curse you now can, once a day while raging, create a 10 foot radius blast with you as its epicenter as an action. This blast deals 3 D10 of your elemental damage type and 2 D10 bludgeoning damage to all targets within you radius, including yourself. All creatures must make a Dex saving through against DC equal to your Con modifier + your proficiency bonus + 8. On a success the creature takes half damage. On a failure, all creatures (excluding yourself) gain the status effect associated with your Elemental Fury. While in your Draconic Rage, your elemental damage die double.

At level 14, you can now perform Dragon’s Blast 2 times per day. You also have advantage on your Dex saving through during your attack.

Mastered Draconic Rage

Through much training and meditation, you can now enter a Controlled Draconic Rage without rolling once a day. With this added control, whenever you enter Draconic Rage you can force anyone you deem a enemy within a 30 foot radius to make a wisdom saving throw against a DC of 6 + your strength modifier + your proficiency bonus. If they fail they become afraid of you and can not move towards you and any attacks they make while you can see them are at disadvantage. To drop the fear effect the can at the end of their turn try to beat your DC.