Warrior Spirit

If a fighter chooses this subclass they learn to push their intense passion for combat to its limits, getting more powerful the more damage they take. The Warrior Spirits fierce determination creates a magical aura that cant be seen without magical assistance. Although it is said if a Warrior Spirits intensity is strong enough their aura can be seen by the naked eye. 

Dynamic Vision

Beginning when you choose this archetype at 3rd level your drive for combat makes you more aware of your surroundings, you gain proficiency in perception.

Spirit Aura

Starting at 3rd level, your intense passion for battle lets you take in damage and then release it with furious intensity. When you activate this ability as an action for 1 minute if you take bludgeoning, piercing, or slashing damage on your next attack you can add the damage you took to one melee weapon attack. The damage added does not have a type. If you take damage from multiple enemies you can only hit back with whoever did the most damage to you. If you are hit multiple times by the same enemy all the damage you took adds together. Once this ability ends you gain one level of exhaustion. You can use this ability an amount of times equal to your proficiency bonus. You regain all uses of this ability with a long rest.

Unyielding Will

Starting at 7th level, the intense energy flowing through you has reinforced your mind and body. You have resistance to psychic damage, and you are immune to being frightened and put to sleep.

Raring to go

At 10th level, your need for combat makes you ready to jump into a fight at any moment, you gain advantage on initiative rolls.

Impassioned Spirit

Starting at 15th level, your Spirit Aura is even more heated than before, now becoming slightly visible. You can now activate Spirit Aura as a bonus action and all bludgeoning, piercing, and slashing damage you take while Spirit Aura is activated can be added together to make your attacks much more potent. Meaning if you take damage from multiple enemies instead of taking the highest damage rolled you add up the total damage.

Ever-growing Strength

At 18th level, the more damage that pounds on you makes your Spirit even more intense, giving you immense physical strength that flourishes into an unstoppable force. For every hit you take while your Spirit Aura is activated you can add an extra +1 to your damage rolls. Once your Spirit Aura ends you cannot re-activate it until you take a long rest and you gain 3 levels of exhaustion.