Ironman (Constitution) (5A)

So, the plan requires me to take a potion that makes me appear dead, drift with the current in the sewer, imitate a corpse as i float by the checkpoint, overcome the poison, fill my mouth with sewer water, and squirt this at the captain, who we know is squeamish? Excellent plan!

An Exemplar subclass. As an ironman, male or female, you have trained your endurance and resilience to be able to survive what would kill others in minutes. As an ironman, you might be known as a food taster, survivalist, courier, or boozer. Famous ironmen from stories include John McClane of Die Hard, Perceval in certain grail stories such as the movie Excalibur (1981).

Level 3: Focus Ability

Your Focus Ability is Constitution. You are proficient in Strength and Constitution saving throws.

3rd Level: Ironman Proficiencies

You gain proficiency with Athletics and martial weapons. If you already know Athletics, you select another skill to learn.

Level 3: Survivor

You can survive under extreme conditions much longer than others.

Add your Exemplar level to you Constitution bonus for such things as surviving without air, food, or water.
Add your Proficiency Bonus to the result of each of your Hit Dice when you gain a Exemplar level. This means you have to re-calculate your hit points each time your Proficiency Bonus increases.
Add your Proficiency Bonus to the amount of hit points you recover each time you heal hit point damage. When you spend Hit Dice to recover hit points, this bonus is added to each Hit Die spent.

Level 3: Ironman Tricks

You can choose these tricks only available to ironmen. You can use tricks even if you are Incapacitated. This includes ironman tricks and general Exemplar tricks.

Invincible. At the start of your turn you can use this trick to end all of the following conditions affecting you: Blinded, Charmed, Deafened, Grappled, Incapacitated, Poisoned, Prone, Restrained, and Stunned. You also end any effect causing damage over several rounds.

Last Man Standing. At the start of your turn you can expend a Hit Die to recover hit points.

Shrug it Off. When you are affected by a spell or ability that allows a saving throw and has a lasting effect, you can use this trick at the start of your turn to make a Constitution saving throw against the save DC of the spellcaster or against the effect in question. If you succeed at this saving throw, the effect ends. You can use this trick even if Incapacitated.

Trap Weapon. When an enemy hits you with a melee weapon attack, you can trap that weapon in your body, including a natural attack. You can use this against opponents you could not normally grapple with, such as one too large or immune to being grappled. The target must make a Dexterity saving throw or become grappled by you. You do not need to use a hand for this grapple. As long as they are grappled by you, they cannot use the trapped weapon, and you have advantage on weapon attacks against them.

Level 6: Ironman Dice

An ironman can spend Exemplar Dice in unique ways. You can do this even if you are Incapacitated.

Spend a an Exemplar Die when you fail a saving throw. Make a Constitution saving throw against the original difficulty, adding the Exemplar Die to the result. If this is better than your original saving throw result, use the new result instead.
At the start of your turn you can spend an Exemplar Die to end any one ongoing effect. Roll an Exemplar Die. On a result of 4 or higher you are no longer affected.

Level 10: Martyr

When a ally within 20 feet takes damage or suffers a harmful effect, you can use a free action to take the effect on yourself. You do this after the result of the effect is known. The ally avoids the effect entirely. The effect now targets you, beginning the process again, with new rolls for attack, saving throw, and effect. You don't benefit from cover when you use Martyr. You can do this three times and regain the ability on a long or short rest.

Level 14: Tit for Tat

When an enemy forces you to take a saving throw, you can use a reaction to force that enemy to make the same type of saving throw against your trick saving throw DC. If the enemy fails this saving throw, they suffer a limited version of the same effect they used on you. If the effect has a duration, the effect only lasts until the end of their next round. If the effect does damage, they only suffer half damage. This does not change the effect on you in any way.