Forever-Walking Warrior

You have trained to be a relentless soldier, able to undertake any situation or circumstance. As a trained soldier, you have learned to overcome your exhaustion, and fight against your own body to push and fight against all of those who would oppose you. 

Your training have allowed you to make your body act both like a candle and a spark, being slow burning whilst being able to burst at a moments notice. The training required to control your stamina and endurance this way is grueling and unmerciful, yet there are some who simply refuse to quit, allowing them to push their physical self further. This type of fighting style requires the sacrifice of the physical body, as you come close to death so often, it leaves your body exhausted and drained, yet soldiers under this training still push further.

Soldiers Endurance

Beginning when you choose this archetype at 3rd level, your endurance is beyond those who use burst tactics, rather you look to slow burning. You can reduce the time of your long rest by 1 hour and still gains it's benefits. In addition, should you take a short rest with no hit die, you regain a hit die.

Tireless Fighter

Starting at 7th level, you can push beyond the restrictions of your body's limitations to keep fighting. You can go 48 hours instead of 24 hours awake before you gain levels of exhaustion. In addition, you can take a level of exhaustion to re-use any fighter features which require a short or long rest to use again, should you have already expended all your uses.

Soldiers Momentum

Starting at 10th level, you have become able to go battle to battle with bursts of energy which seem to come from nowhere. Whenever you use your Second Wind feature, you can use your reaction to gain an extra attack and 15 feet of additional movement for the turn you use the Second Wind. Once you use this feature, you cannot do so again until you take a short rest.

Forever Walker

Starting at 15th level, you, in a sense, become resistant to exhaustion itself. Whenever you take a short rest and have levels of exhaustion, you can make one Constitution check against a DC of 18 + level of Exhaustion you are at. Should you succeed, you reduce your level of Exhaustion by one. You can do this once a short rest. You can instead choose to expend 3 hit die to reduce your Exhaustion by 1.

In addition, your resistance to exhaustion allows you to fight its effects. At 1st level exhaustion, you select an ability check, and do not gain the disadvantage to it. At 3rd level exhaustion, you select a saving throw, and do not gain the disadvantage to it. At 5th level exhaustion, you drop to 10 feet of movement instead of 0.

Power in Exhaustion

Starting at 18th level, your exhaustion becomes a channel for power, as you become more desperate and filled with fury in you exhausted state. For every level of exhaustion you have, you gain a +3 to damage rolls. In addition, you can gain a level of exhaustion as a bonus action. When gained this way, the effects of the level of exhaustion take effect at the end of your next turn instead of immediately, and you have advantage to all attack and damage rolls until it does so.

Finally, your resistance to exhaustion allows you to live further without rest than others. You instead have 7 levels of exhaustion, pushing each normal level up by one (e.g. 6th level death effect is now 7th level). Your new first level of exhaustion has no effect on you.