Way of Iron

Monks who follow this path not only strengthen their body to be like iron, but their mind as well. They train the body and mind with mental and physical practice to the point where both are at peak perfection. Their body enough to withstand the hardest, even fatal blows, while their mind is strong enough to heal their physical person. 

Skin of Steel

You gain resistance to slashing and piercing damage. 

Iron Mind

At 3rd level, because of your mental practices that made your mind as a sword's iron, you can add your Wisdom modifier to Wisdom ability checks and saving throws. 

Strength of Metal

At 6th level, when you make an unarmed strike, you can spend 2 ki points to force the target to make a Strength saving throw (DC 15) or be knocked prone. 

Unbreakable Will

At 17th level, because of your years of mental training, your mind has been strengthened that it is now like solid metal and your physical form the same. When a creature causes you to drop to 0 hit points, you can spend 6 ki points to instead drop to 5 hit points and make a burst of ki energy, dealing 2d12 Force damage to each creature within a 50th foot sphere. You cannot use this feature again until you finish a long rest. 

Healing Mind

At 11th level, your mind is strengthened even more, even enough to repair your physical body and perfect it once more. As a bonus action, you can spend 3 ki points to regain hit points equal to your Wisdom score. You can't use this feature again until you finish a short rest.