Sacrifice, Pain for Pain 
your monastic tradiction uses the harshness of pain to improve your attacks and body.
You give and you take.

Sacrificial Body

Your monastic tradiction demands a strong body to take up whit the pain you are trained to receive.
Starting at level 3 you gain the following benefits 
You gain +2 hit points per monk level 
You can use either Constitution or Wisdom on your unarmed defense feature.

Sacrificial Rituals

Your monastic tradiction have rituals, ways of being and act,  starting at lvl 3 you gain the following ritual options.
You cant benefit for more than one ritual at the same time.

Ritual of Pain
As a bonus action you can take up to 3d4 necrotic damage (this damage ignores resistances and imunities. for each die you gain +1 bonus to damage and attack rolls, for 1 minute

Ritual of Recovery
As an action you can spend 3 ki points enter into a meditative state, while on this state you cant take attack actions or cast spells,
while on this state you have regeneration equal to your constitution modifier, for 1 minute

Paralizating Pain,

Starting at level 6 if you are under any of your Sacrificial Rituals effects you can spend 5 hit points instead of ki points to use your stuning strike feature if the creature suceed the saving throw you regain the hit points you use
if you stun a creature in this way that creature instead of stuned is slowed as per the slow spell for the next minute
in adcition you can use your constitution modfier instead od wisdom on the stunings trkie saving throw dc

Proficient on Ritual Practices

Starting at level 6 you gain proficiency on a skill of your choice betwen arcana history or religion.

In addiction you learn a 1st level ritual spell from any spell list which you can cast as ritual

Sacrificial Rituals ( Mastery )

Your monastic tradiction have rituals, and your learning and improving on them, starting at lvl 11 you gain the following ritual options.
You cant benefit for more than one ritual at the same time.

Ritual of Equilibrium
You can as an action enter this meditative state, while on this state you gain the following benefits for 1 minute
If you fail a saving throw or skill check, you can declare you want to spend your hit points to try and make up the difference, after which the DM will tell you what the DC of the skill check or saving throw was, and you may pay hit points equal to the difference between what you rolled and the required number.

Ritual of Blood pouring
For the next minute When you make an attack roll on your turn, you can choose to take 3d6 necrotic damage (which ignores resistances and immunities, and cannot be reduced in any way). The roll to hit and any damage you deal with this attack receive a bonus equal to the amount of damage you took.

Ultimate Sacrifice Ritual

Your monastic tradiction have rituals, and your learning and improving on them, starting at lvl 17 you gain the following ritual option.
You cant benefit for more than one ritual at the same time.

Bloodbath Ritual.
for the Next minute you can as part of an attack action spend all your hit points until you fall to 1, if you do so you ignore the targets AC, then your target takes damage equal to the doble of the hit points you spend. in adiction the target take 2d6 necrotic damage on the start of their turn for the next minute this damage ignores resistances and imunities on both you and the enemie.