Decay

Soul Siphon

Starting when you choose this tradition at 3rd level, you can manipulate your enemy’s vitality when you harness your ki. 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 make a constitution save, on a failed save the creature’s max hit points are lowered by the amount of damage dealt by the flurry of blows 
• The user heals the damage dealt by the flurry of blows 

Necrotic wound

At 6th level, you learn how to Infuse your necrotic Touch in your attacks against creatures that are injured 

When damaging a creature that is below half its health you do an extra 1d6 necrotic damage time that creature 

Soul Devour

Beginning at 11th level, you learn how to take another’s life force and add it to your own.

When You knock unconscious or kill an enemy creature with a melee attack you can use a ki point to gain 3d8+wis mod health, up to half your max health. 

Active decay

At 17th level, you gain the ability to set up a lethal strike that infects the targets life force. 

When you hit a target if you spend a ki point you can force them to make a con save if they succeed they are immune to this effect for the next hour, if they fail they take an extra 1d10 necrotic damage at the start of the targets turn. This effect may stack on itself and if the target is already effected then the target does not make a save for the additional times it is effected it only makes the save for the first effect.