When a creature wearing armour or that is one or more size categories larger than you attacks you, you can spend a Ki point as a reaction, if you do all attacks made by the creature against you this turn are made with disadvantage. 

Soup for my Family

At 3rd level, attending protests and demonstrations has given you skill in avoiding attacks from powerful opponents and using any object to hand to defend yourself and others. ​

You gain proficiency with Improvised Weapons, and any improvised weapon you use qualify as a Monk Weapon and gain the thrown property.

Additionally, when a creature wearing armour or that is one or more size categories larger than you attacks you, you can spend a Ki point as a reaction, if you do all attacks made by the creature against you this turn are made with disadvantage

Fistful of Steel

At 6th level, you learn how to direct Ki through plexiglass, kevlar and ceramic plaiting. When you make against a creature wearing armour or that is one or more size categories larger than you, you can spend 1 Ki points, if you do all attacks you make against that creature this turn are made with advantage.

Agitator's Strike

At 11th level, exposure to tear gas, flashbangs and tasers no longer faze you.

You cannot be Blinded, Deafened or Paralyzed.

Additionally, When you use your Stunning Strike ability against a creature wearing armour or that is one or more size categories larger than you, that creature makes their saving throws with disadvantage.

Batter up!

At 17th level enduring volleys of grenades and beanbags has gives you expert know to redirect them back at your opponents.

When you use your Deflect Missile ability to successfully reduce the damage of a missile attack to 0, you may have the missile rebound to hit a number of targets equal to your Wisdom Modifier.

You make a separate attack roll for each creature, and if an attack fails to hit a creature the missile stops and no further attacks are made.

If a creature wearing armour or that is one or more size categories larger than you is is hit with Deflected missile attack, it takes max damage.