Embodiment of Wrath

A god of war or destruction has granted you powers to be their bringer of destruction and pain. Your wrath burns with a dark intensity, making you seem more blessed by demons than gods. 

Sword of Chaos

At 3rd level you've learned to handle greatswords with one hand without them having less of an effect, you can use them with two hands, in which case they deal 2d8 instead of 2d6. While wielding a Greatsword in 1 hand you are not able to use shields as these would inhibit your movement.

Additionally when raging, your weapon glows red hot, allowing you to either deal your weapons damage or fire damage for your rage damage

Fiery Constitution

Your armour class equals 10 + Constitution modifier + half your proficiency bonus, rounded up.

Additionally you gain resistance to fire damage.

Gauntlet of Destruction

Starting at 6th level, when raging you can have your offhand take on a rugged metallic appearance, increasing in size, appearing like a demonic gauntlet.

When raging this grants you a +3 to your armour class, additionally unarmed attacks dealt with this hand deal 1d4+Strength modifier damage. You are unable to wield your greatsword twohanded while your offhand is transformed in this way.

Burst

Starting at 10th level you can use an action to unleash a burst of divine energy through your sword or your gauntlet. You can use this feature when you rage, and an amount of time equal to your Proficiency bonus, regaining all uses on a Long Rest. Strength is your "casting" ability for this feature.

•   Sword: You stab your sword in the ground, in a 15ft radius around you fiery swords burst out of the ground, creatures caught in this must make a Dexterity saving throw or receive 2d8+your Strength Modifier fire damage, halved on a successful save. 
• Gauntlet: You slam your fist in the ground, causing a shockwave in a 15ft radius around you, creatures caught in this radius receive 1d8+ Your Strength Modifier in thunder damage and must make a Strength Saving throw, on a fail they are knocked prone.

Your Gauntlet now deals siege damage. 

The damage of this feature increases by 1d8 at lvl 15.

Embodiment of Chaos

Starting at 14th level you are able to use 2 rages to channel your rage to an even greater extent, you take on a fiery demon like form. Your size increases by one size, you deal an additional 1d4 fire damage on your weapon attacks. The radius of your burst ability increases by 5ft. while in this form. Additionally any creature attacking you receives your rage damage in fire damage. This form remains for 1 minute or if you exit it using a bonus action. When in this form you gain resistance either Necrotic  or Radiant damage and immunity to Fire damage.

The additional damage increases to 2d4 at 18th level. 

In addition when raging you can make your melee weapon attacks deal only fire, necrotic or radiant damage.