“Loud stubborn braggarts trained to survive in the monster infested wilds of the god forsaken mistpool. Their bravado is staggering but not baseless, for their achievements speak for themselves. It takes a new form of insane to reinforce your body by repeatedly punching a stone wall and only considering yourself ready once you have punched through it. I have dedicated my life to meditating and discipline but even I lack the willpower to fearlessly laugh in the face of a dragon after I punched it in the nose. If the iron fists prove anything, it is that even a monastic life is better lived with a smile on your face. The future of the monastic orders is in the hands of people who will reshape the world for the better. I truly believe that.”

- Abbot Shandalar Nyhanar of the Dusloska monastery of the Open Palm.

Fists of Iron

When you choose this tradition at 3rd level, The painful training you have endured allows your strikes to push past the limits of your body.  
As a bonus action, as a feat of willpower, your fists take on a metallic appearance. For the duration you gain the following abilities. 

• Your AC is increased by 2 as long as you are not wielding weapons or a shield
• You can use your Wisdom modifier Instead of your Dexterity and Strength modifier for the hit and damage rolls of your unarmed attacks.
• You can use your Wisdom modifier in place of your Strength and Constitution modifier when making Ability Checks and Saving Throws.
• When you make an unarmed strike with your action, you may add your martial arts die an additional time when rolling the damage. 
• Your unarmed attacks deal double damage against objects and structures

This ability’s duration is 10 minutes and ends early if you are knocked unconscious. When the duration ends you can spend 1 Ki-points (no action required) to increase the duration by 10 minutes.
You can use this ability twice. You regain all uses of this ability upon finishing a long rest.

Tempered Body

Your training has caused you such unfathomable amounts of pain that your mind has learned to resist and ignore it. Through sheer willpower your body becomes impenetrable. You have no use for dodging when no blow can 

Starting at 6th level whenever you are dealt damage you may as a reaction spend 1 Ki-point to gain resistance to all damage until the end of your next turn. 

Alternatively you can spend 4 Ki-points to completely negate any damage received until the end of your next turn..

Also starting at 6th level you regain all uses of your Fists or Iron ability on short rest as well as a long rest and you can add your Wisdom modifier to the damage reduction of Deflect Missiles.

Bullet Punch

Through discipline and training your attacks are fast enough to break the sound barrier. With such speed you are able to send the power of your attacks across long distances.

  At 11th level you can use your action to punch the air, creating a shock wave that flies towards a target you can see within 60 feet of you. Make an unarmed attack against the target. On a hit you deal force damage equal to three times your Martial Arts die. Before rolling the damage for this attack you may choose to spend up to 4 Ki-points. The damage is increased by one extra martial arts die for each Ki-point you spend.

Also starting at 11th level your Ki save DC is permanently increased by 2 and the duration of your Fists of Iron ability is increased to 1 hour and whenever the duration ends you can spend 1 Ki-point (no action required) to increase the duration by 30 minutes.

Volley of Fists

At 17th you reach the pinnacle of what your endurance training can provide you. Your body is a fortress, your fists are battering rams and your willpower is unbreakable. As an action on your turn you may do a Volley of Fists. Choose one target within range and make 5 unarmed attacks against that target. You may use this ability twice until you finish a long rest. You may also spend 3 Ki-points to use it an additional time.

Also starting at 17th level your Fists of Iron ability lasts indefinitely as long as you are conscious.