Unbound Chaos

Maybe you were born with it, or maybe this sort of magic manifested only once you let your rage become out of control- or your nightly dreams consist of the sparks of steel on steel combat and the showering blood, to the tune of gunshots and smell of black powder in the air. Maybe causing trouble is just how you feel natural. 
Either way- the world itself deems you worthy of granting you magic to stir up the mundane nature of the land. Combat is your blood and uncertainty is your language. 

Steel and Blood

Your innate spellcasting, love for combat, and arcane visions of war manifest in your spells and proficiencies.

At first level you gain  proficiency with all simple and martial weaponry. As well as shields, light, and medium armor. 
At level 6 in this class you become proficient with firearms as well if they’re available. 
You also gain access to the Paladin spell list- any spells you pick count as sorcerer spells and use your spell slots as normal. 

Spark of Chaos

As per your description your character’s appearance suddenly alters to what you describe (but not enough to grant any exclusive changes). 
At the start of your turn you can expend 3 sorcery points and begin your “Spark of Chaos”. After doing so your movement speed becomes 0 until the start of your next turn. 

While in your ”Chaos Form” you gain additional benefits for the next 10 minutes- 

• You have advantage on Charisma (Intimidation) checks. 
• You have the capability to cast more than one spell per turn, provided the casting times do not overlap.
• You gain resistance to all damage types however- any saving throws regarding Intelligence, Wisdom, or Charisma are done at disadvantage regardless of any effects or advantage gained.

Your Chaos Form ends early if you are charmed, incapacitated, or unconscious. 

Disorderly Mind

At 14th level you have the capability to concentrate on 2 spells at once- however while doing so your concentration saving throw is done at disadvantage and unable to be altered in anyway. If you lose concentration both spells are lost. 

Havoc’s Respite

During a short rest the amount of HP restored via Hit Dice also replenishes the amount of Sorcery Points used. 
This feature can only be used once per long rest. 

Extra Attack

You can attack twice, instead of once, whenever you take the Attack action on your turn. Moreover, you can cast one of your cantrips in place of one of those attacks.