I was thinking of making a monk feat, but let’s build on what we got going on with the Way of the Open Hand.
Way of the Cracked Turtle
Monks of the Way of the Cracked Turtle have learned from the simple turtles around them While slow, their steady path leads to victory. They toughen their bodies to be the bulwark necessary to bear the brunt of the world on their shoulders. They also learn the way to crack false armor while others bend under the weight. It is truly turtles all the way down, for these men and women are tireless companions and will carry those around them to victory.
Starting when you choose this tradition at 3rd level, you learn how to harm those who bare false shells. Whenever you hit a creature with one of the attacks granted by your Flurry of Blows, you can impose one of the following effects on that target:
- It must succeed on a Constitution saving throw or you impose a penalty equal to half your proficiency bonus for one round to AC.
- You toughen yourself and gain a bonus to AC equal to half your proficiency bonus.
- You block its movement and prevent it from making one action this round if it fails a Wisdom saving throw.
Lessons of the Turtle
At 6th level, you training truly begins to take off as you gain a permanent bonus to AC equal to half your proficiency bonus.
Beginning at 11th level, you can enter a special state of determination. As a free action or reaction, you can choose to not fall unconscious. This state will end when you die from exhaustion, failing three death saving throws if you are at zero hit points, or you end this state as a free action. If you are magically healed while in this state, all your failed death saving throws are reset to zero.
At 17th level, you truly become the turtle. Gain a swim speed equal to your land movement speed or vice versa. You also gain an additional bonus to AC equal to half your Constitution modifier. Furthermore, when you make an attack with your flurry of blows, you may make one more additional attack using a bite.