Way of the Imprisoned Soul

Most monks train for years to release their ki into beautiful displays of martial arts and magic. Monks that follow the Way of the Astral Self discipline channel their ki into entire bodies that fight alongside them. Monks that subscribe to the ideals of the Way of Mercy use their ki to heal broken wounds by manipulating the presence and qualities of the flesh, or to disrupt the natural human order using their ki. The Imprisoned Soul scoffs at this ideal. Ki can be used to create, but its truest potential is unlocked when used to imprison. These monks typically go through extreme amounts of physical training in order to compensate with other Orders, as Wardens (the nickname given to these monks), refuse to use their ki for magic. This results in monks that are far more physically trained, able to stand up against spellcasters and ancient dragons. 

Chained Soul Technique

Starting when you choose this tradition at 3rd level, you can manipulate your enemy’s ki when you harness your own. Whenever you hit a creature with one of the attacks granted by your Flurry of Blows, you can force them to make a Wisdom saving throw. If they fail this saving throw, they take force damage equal to your monk level, and cannot take any other actions on their turn besides the attack, help, or dodge actions.

In addition to this, your maximum HP increases by an amount equal to your level, and increases further by 1 every time you level up. In the same time, whenever you kill a small or larger hostile creature, you gain temporary hit points equal to your monk level.

Adaptive Toughness

At 6th level, your body toughens to compensate for the lack of magic.  Your fists and feet become harder than iron. Your martial arts die increases by one step (d6 to d8). At 11th level, it becomes a d10, and at 17th level, it becomes a d12. This increase only applies to your unarmed strikes, and if you attempt to use a weapon, it only deals 1d6 damage or its original damage.

Legendary Imprisonment

Beginning at 11th level, your Chained Soul Technique is enhanced to restrain those of legendary or mythical status. When you use your Chained Soul Technique, you may restrain a creature from using its most powerful abilities. Creatures with legendary actions cannot use their legendary actions for a number of turns equal to half the amount rolled on your martial arts die.  

Perfection Incarnate

At 17th level, your physical form transcends to its truest state. Your constitution and dexterity scores increase by 2 each, to a maximum of 22. In addition to this, your attacks ignore immunities to bludgeoning damage, and deal additional damage equal to half of your constitution modifier (rounded down).